mercury vapor lights

hi i was just wondering if anyone experimented with mercury vapor lights for vegin. i just seen them in a isle in with metal halides and was wondering.

I use mercury vapor lights and when I want to replace the 1000watt bulb it was a metal halides and it works good for me

but if I was to do it again I would use HPS

ok its just i seen some self-ballasted mercury vapor lights and was wondering how good they were cause you dont need a ballast for them.

thanks for the input +rep