You'll get the idea once I explain below

I seem to notice color temps even if it's like 300K apart (ex. 2700K and 3000K)
Terrible lighting installations \
The 60Hz flicker that comes from any magnetic ballasted light source
MH lights seem to have a colored flicker, the colors consisting of RGB
That small buzz that comes from the electronic ballast in a CFL
Multi-colored light sources (Fluorescent, MH, HPS)
A small change in lighting (If one light source were to go out, I'd notice it)
If a light source has a flicker or not
(Something I do on my own) Stare at any HID arctube for so long that I eventually see the arc
Can distinguish the difference from Incandescent, Fluorescent, and LED without seeing the light source
Figure out how a place is illuminated (Use Metros for example)
Sees the heat haze coming of  or any HID

i can agree with all of this

I can notice "light quality" changes which are not related to color temperature or CRI. Things like, how well the light does or does not cover the needed color range to see what is under the light, and whether it does or does not call on information completion for the color rendering

I can notice flicker of 100 Hz, but only when it's duty cycle is low. That means, that i don't normally see the flicker of properly working Fluorescent and HID lamps, but i do notice very well through the flicker when something is wrong - to the point where others can't do it, and even (in a recent case) when it couldn't be caught even by a camera. Back when i was using CRT monitors, i was feeling comfortable using them with vsync frequency of 85Hz and higher

And i can agree with all the rest..

All the points brought forward by F96, I can relate to. Here's some of my observations in this area :

I notice that CFL light quality is not right. Difficult to explain, but it lacks some spice and can make the space kind of drab.

LED is only very slightly better. It is usually too blue for my taste, even the 2700K ones. There is not a whole lot of excess blue, but just a slight amount but I can see it most of the time.

Metal halide has none of those. Quartz metal halide maybe but there is some kind of 'compensation' in the red part of the spectrum that 'neutralizes' at least some of the excess blue. That makes ceramic metal halide my favourite indoor lighting, most of the time.

Now, glare is another one. Commercial spaces that have recessed troffers with prismatic lenses can get hard on the eyes. Suspended direct/indirect fixtures (such as the old fashioned louvres) are much easier on the eyes. Most people have no idea when I bring up the subject (which I seldom do).

My room at work has troffers and the glare can get very annoying. I put a small table lamp on the side opposite of the windows, and the light source at eye level sort of balances out the unevenness of the sight lines, and the glare is much more bearable (not to mention that it is a CMH lamp in there).

I notice that CFL (and all Triphosphor Fluorescent) light quality is good, second only to Metal Halides of different types

LED is far worse. It appears to have "spice" and so does not appear at first to be missing anything, but it only consists of the "spice". It silences weak shades of color, subsituting its own light color instead. The CFL lacking spice leaves them alone and they appear approximately right

Yes, LED has an initial wow factor which quickly goes away when you notice the subtle colour mis-renditions. Most people don't notice or don't care.

Not so much to do with the light source itself, more the design of most of the fixtures I've seen. The vast majority of the LED fixtures around here have NO optical control whatever, they're just glare bombs, pure and simple. The colour temperature of them is also WAY too high.

Maybe if some thought was put into them, I wouldn't detest them so much 

Most LED lighting around here are retrofit. The original (often discharge) lighting was carefully chosen by the architect in consultation with lighting specialists. Most of it was done very well. The LED retrofits are done by maintenance heads that must heed to the bean counters, they must change to LED, and they don't hire a specialist to make it properly. Glare and inappropriate colour temperatures abound. Sometimes, they don't really reduce the overall system wattage, depending on how it's done (or they greatly reduce it along with the lumen count). But it's LED, that is what the people want, and most are happy with it. I'm sure if you interviewed a sample of regular customers to a store that has had a bad retrofit job, most would agree that it is an improvement but you'd have to tell them it was done otherwise they wouldn't notice anything different from before the conversion...   

Also, most people don't notice a mixture of colour temperatures, which usually happens with fluorescent (but I've seen it with metal halide as well).

I asked a friend of mine about cycling hps in his neighborhood and he thought the motion sensors on them were defective.

I've had a similar "explanation" once regarding outdoor staiway hps cycling lights. There were six, three on either side outside a building at university. Thay all cycled. The person was saying it was done on purpose to save energy while having the lamps wear evenly. Some people just don't understand.

Haven't they heard of streetlight interference ?

I notice all sorts of small details about a place's lighting:

What kind of light (Incandescent, CFL, Halogen, or LED)

The wattage and lumens if it is present

Color temperature, and if it is suitable for the given environment.

County of manufacture (I'm excited to see some LED's being made other places besides China)

Brand (I'm a Philips fan)


For incandescent lamps, I pay attention to small details that make up what is essentially an "ordinary" light bulb:

Filament structure (vertical or horizontal, supports or no supports)

Soft white or inside frost (I much prefer the soft white coating with silica)

How thick or thin is the soft white coating, and does it vary from bulb to bulb within the same package?

Date code and country of manufacture

Not so much to do with the light source itself, more the design of most of the fixtures I've seen. The vast majority of the LED fixtures around here have NO optical control whatever, they're just glare bombs, pure and simple. The colour temperature of them is also WAY too high.

Maybe if some thought was put into them, I wouldn't detest them so much 

Couldn't agree more sweetheart.