me i like MP for street lighting but long gone now.
but MV make great yard light and up lighting in trees at night

 HPS is great for accent lighting as well and where CRI is not important

 sox lighting is good too ever lower wattage and the lowest CRI where is very unimportant

 metal halide is good for where you need a lot of light and when best to do group replacement
 every 2 or 3 years

  out of all of them i like mercury vapor becase it the lighting hid lighting that i grew up with.
 and last the longest.

I like MH for the color rendering for large scale indoor lighting and high end retail lighting (especially with the CMH for retail), but their lumen maintenance is terrible.  They are pretty efficient when new, but it means nothing after a couple years.

MV is actually a better choice over MH for outdoor use I think, since they have a much better lumen maintenance even though they don't start out as bright as an equivalent wattage MH when new. The color rendering is plenty sufficient, especially with good phosphor coated lamps, and works the best out of all the other lamps when the light level is low.

I have no problem with HPS.  I think for highway and security lighting it's the best compromise in lifespan, light quality, efficiency, and cost. Probably why it is so common.

Of course LPS is my personal favorite, just because it is a really cool lamp from a technologic standpoint and they are so uncommon, making it such a pleasure to see them running.  They do have certain very good strengths such as low glare, high contrast, very high efficiency, 100% lumen maintenance, instant restrike, very cool running, and good visibility performance in bad weather.  They are a bit more expensive, even at 1000bulbs prices, are more difficult to design good performing fittings for, perform very poorly at very low light levels, and not as long lasting. They have their place for fog prone areas or other generally poor visibility conditions, dark interchanges and intersections out on the highways (but HPS often does sufficiently well here), low running cost tunnel/parking lot/security lighting (the energy cost really works in their favor for those 24hr running very long tunnel installations such as the Baltimore harbor tunnel). They can really put out the light, but will certainly look dim in poorly designed and maintained fittings.

All in all for personal use, MV is great for indoor lighting in my room.  I like the sort of old fashioned "industrial" feel it gives and is great for getting stuff done, or just chilling.  Not too attracted to MH, as their run up is not that interesting, and the light quality can easily be had with good fluorescents or CFLs, but I'll run a 400W one up every now and then just to enjoy the shear level of light.  Never messed with HPS but wouldn't mind getting my hands on one sometime.  LPS just makes me feel good at the end of the day.  It has that kind of vintage "quiet snowy street out in Europe somewhere" mood and is very enjoyable to watch run up.  It's also excellent for seeing well in the dark.  My 55W FCO fitting is currently out in the backyard at home for playing badminton at night.  It's actually easier to play under that than in the daytime (another case where HF really helps out! no 60Hz birdie flicker! ).

I notice quite pronounced flicker with MH's in indoor use - which does not happen with fluorescents (even magnetic ones). This is not noticable in outdoors MH

So i'd prefer fluorescents over MH for indoor use

Ash: Mercury and MH lamps, tends to be more flickering in vertical burning than in horizontal burning.

I think it matters what ballast it is on, the HX/NPF may flicker, and it is probably due to factors such as line loading. (magnetic ballasts with capacitors don't flicker as much as those that don't, especially for the case of fluorescent ballasts.)

The fixtures where i seen this harsh flickering (highbays) use superimposed ignitor (as i hear them buzz if lamp is missing) and run on 240V 50HZ. Other than that i dont know what the gear is

What is interesting, the flicker is not visible in MH fixtures (even similar ones) running outdoors, and in (magnetic) fluorescents whether indoors or outdoors

What make the difference is, how much is the ballast conductive for the DC current (eventually propagate the DC component to/from the mains, like series choke) or not (have the capacitor in series with the lamp).
Vertically burned lamps have the tendency to slightly rectify (the voltage drop is slightly different in one direction then the other one) and the question is, how large DC current component this asymmetry create.
Series connected capacitor (CWA, many higher power fluorescent 120V HPF ballasts,...) obviously do not let any DC component to flow through the lamp (the capacitor block it)
What could make some difference is ballast wire resistance in the lamp circuit - the wire resistance is the only thing, what limit the DC current flow, but at the same time this resistance is the cause for losses in the ballast.

I do not believe, then the presence of the capacitor parallel to the mains side could make any difference in lamp flicker at all.
But the difference would be between multi-voltage ballast designed to work with such capacitor (so designated HPF) and the one designed to work without (NPF). The capacitor, when connected across the whole primary (e.g. on the 244 or 277V tap), reduce the power dissipated in the primary winding, so the "HPF" ballast design may afford higher losses in the secondary winding (all ballasts of the same grade and size are designed to about the same power dissipation), so higher resistance in the lamp circuit. The consequence is then lower DC current component (for the same DC voltage component dictated by the lamp asymmetry), hence the lower flicker of the "HPF" ballast.

@ Ash: Was the fixture (fluorescent) have a HPF ballast?
Also, fluorescent powder sometimes have a persistence, causing steady stream of light.

The fluorescent fixtres are all Switch Start or Perfekt Start on 240V - just series inductor with the lamp

In HPF fixtures the power factor correction is done with a capacitor parallel to the mains so that all of the fixtures (even HPF) behave like NPF for the matter of your question

Phosphor presistence is quite short, but still could be a factor (compared to MH)

Metal Halide
- They have the best CRI and rendering among streetlight HIDs.
- I especially like the warm-white ones that mimic incandescent.
- But: a lot of UVs that make them not recommended for long-term use.

High Pressure Sodium
- I don't like the colour of regular high pressure sodium bulbs.
- However I like white sodium that mimic incandescent fairly well (yes I'm an incandescent bulb guy!).

Low Pressure Sodium
- I love this one for nostalgia! Reminds me the 1980's highways and some streets...
- It's funny to see everything black & white (black & yellow actually!).

Mercury Vapor - Fluorescent Coating
- Another one I'm nostalgic of! Great moments under this light!
- Mercury vapor street lighting looks great IMO: natural white colour plus acceptable CRI.
- Warm white mercury lamps are pretty rare but they look nice.

Mercury Vapor - Clear
- I discovered those lamps a couple of years ago.
- I like them because they give an ugly vintage tint to everything!
- I don't understand the benefit compared to fluorescent coated lamps: promoting other HIDs that don't make people have greenish skin?!

Nice answers everyone!  I really like the MH color output, however I am very dissatisfied with the average life hours of them.  I rarely can get up to 10,000 hours out of them, and I've had a few explode at EoL. Not fun. 

@RyanF40T12:

MH lamps can acheive 10000h IF burned (used) BASE UP or VERTICAL.

@Cavannus:

MH lamps do not make any more UV than a MV lamp (unless it is a UV MH).

Metal Halide
- But: a lot of UVs that make them not recommended for long-term use.

The amount of UV is about the same as from the MV of the same lumen output. What only matter is the UV-A, other are quite well suppressed by the outer bulb.

Mercury Vapor - Clear
- I don't understand the benefit compared to fluorescent coated lamps: promoting other HIDs that don't make people have greenish skin?!
[/quote]
The small size of the light source, so allow better beam control, so higher optical efficiency of the lantern and less spill light. With matched optics the useful efficacy would be the same or even higher then of the fluorescent ones.
Other benefit is mainly for observatories: Few Hg lines are quite easy to filter out in the telescope, while (unlike the LPS) the possibility of better beam control could achieve less needed lumens, so in that way less light emitted upwards to the sky (then with LPS).

That's the problem then. All of these are wallpacks

http://www.rabweb.com/product_detail.php?product=WP2CH150PSQ/PC

@RyanF40T12:

MH lamps can acheive 10000h IF burned (used) BASE UP or VERTICAL.

@Cavannus:

MH lamps do not make any more UV than a MV lamp (unless it is a UV MH).

That's the problem then. All of these are wallpacks

http://www.rabweb.com/product_detail.php?product=WP2CH150PSQ/PC

Quote from: LowPressureSodiumSOX on February 06, 2012, 03:31:29 PM

@RyanF40T12:

MH lamps can acheive 10000h IF burned (used) BASE UP or VERTICAL.

If the bulb is rated for horizontal (or universal) burning, there would be no problem, the difference is not as large. What differ between horizontal and vertical position of the "universal" lamps is the light color. Therefore the whole installation have to use the same position, otherwise each fixture would have different hue and that would be disruptive.

So in your case, as all your fixtures are horizontal, you do not have to worry at all.