Are all CMH bulbs the same, qualitatively speaking?

very little difference - except for price - pm

I you're looking at CMH then you need to look a venture uni-form halide pulse start - the 950 series is just like sunlight, and the PAR (that I actually measure) is astronomical. plus this is a commercial lamp, so the price is not astronomical - $45-50 for a 575 watt lamp that lasts for 20,000+ hours, and puts out HUGE PAR! the ballast will cost you 120, but you'll need to get a case and cord etc., but it comes with the wiring diagram which is very easy to put together.
I use the Lumenmax reflector, because it is excellent, and very reasonable.

My friend as bought a new ballast system. They run very quiet and use less electricity than other style ballasts. We can use 24 600W bulbs instead of 10 600W bulbs in the new system, he say he get double amount of bud, while using same amount of electricity. so "buyorsell888" you can prefer the same ballasts as my friend prefer.