I just got done with an installation of new Venture 350w uni-form pulse high bay fixtures, these fixtures include this lamp;     http://www.venturelighting.com/LampsDataSheets/PulseStartMetalHalide/71329.pdf
and the matching Venture 350w pulse start HX-HPF magnetic ballast.
One interesting thing I noticed is that these lamps have an extremely fast run-up for a quartz lamp on magnetic gear, I clocked 50 seconds from initial cold start. Also it appears that Venture uses some sort of emissive coating on the electrodes like mercury lamps as they do not glow incandescent on start up. When started, the lamps look exactly like a mercury lamp with no electrode glow at all, there is no pink argon flashes, just an instant, stable mercury discharge. And the halide salts start vaporizing 20-30 seconds in, another 20 seconds and the lamp is at full output. How is this possible with magnetic gear. Venture must be doing some proprietary thing that other lamp manufacturers dont know about. Also there is no end paint on the arc tubes, very unusual for a Na-Sc lamp. The ballasts are dead silent too, I had my ear within 1" of the ballast box while it was running and I couldn't hear any hum, was truly silent. Unfortunately there were no extra lamps or fixtures for me to take home to test/experiment with.

Also I thought 30,000 hours was unusually high for a quartz lamp, but if the electrodes have emissive coating then there should be low sputtering and therefore longer life. They must've created an emissive coat that is non-reactive with the halides

I ilike Venture lights,too.Have 250W,400W and 450W.These are the lights I use most.Great color,and the fast warmup.I have some 400W bulbs that are several years old-still going strong.

The fast warmup is generally a result of the ballast load characteristic. If you manage to have the current significantly increasing if the voltage decreases below the range of normal burning voltage, it yields faster warmup. With an electronic this is piece of cake, but it is possible to achieve with just the "core and coil" technology with some help of some parts of the core saturating (so the OCV still remains high). It would be some sort of "mag-reg" topology (saturable both stabilizing coil (with the capacitor), as well as the shunt between the stabilizing and secondary)...

These lamps are fantastic. I've been running mine for over 3yrs now (about 6hrs/day November through March-150days a year) and have seen only about a 10% drop in lumens. I use a Venture V90J7512 ballast (attached).

What Medved said should be right, plus I'm sure that the design of the small arc-tube (it's nearly 400w HID tube but quite small) might also have something to do with the short run-up. The vertical operation must be related to the long life. It's one of my favorite citrus lights I'm running as, yes, it's quiet and the shop-light reflector I use concentrates the light nicely down to my plants without spill.

According to the pictures it is "just" a common CWA, so the faster startup goes really only on account of the smaller arc tube (compare to probe MH).

But I just have paid more attention on how my 150W quartz MH (pulse start, as I'm in Europe; some Cheepeese made...) starts and it really reaches the final brightness in less than a minute, so that could be quite common for the pulse start lamps.
Maybe the ceramic ones (the ones I made most of my experiments) are again a bit slower (more light going out, so less heat remains within the arc tube, higher operating temperature,...), but not that much.
Definitely way faster than MV's or still faster than HPS...