I've had a Lumitek 600w for abt 3 years and 2 Lunitek 1000's for abt 6 months in a partnered grow that have worked fine, except for a bulb compatiabiliy problem with the 600w ( it would eat Hortilux bulbs). That problem is more a product of the bulb then ballast. Having never used any of the others, I can not say which is "best". I would suppose that how cheap you can get a particular brand vs. it's reliability influences which might be deemed best.

GaGrwon raises a valid point, HF being last out, you would hope they'd copy the best of what went before.
OM