I have been running old Spectra 180 off and on for about 4 years now, in a small tent with one 180 I vegged up to 12 plants nicely, BUT size was not the same as a good 400 MH. I also tried flowering but gave up after a while and went to 600 HPS. MUCH< MUCH happier ... Maybe four years later things are different but not willing to give up quantity - quality for just possibly quality.
I think things are changing fast and HID will gradually be replaced by newer technology. My new lights are comparable to a 600, especially since the reduction of heat will help a lot of smaller growers who have a hard time dealing with that because of space or cost limitations. I would bet most small HID grows are compromised by heat related issues, both yield and quality. I love my 600s and grew with them for years. I was pretty hesitant to plunk down the coin for these newfangled things, I'm not much of a gambler, but they are pretty darned good. That's 2014 technology and, like I said, things are changing fast. Affordable 1K replacements are only a couple years out.
Okay, off soap box. Hiya, sixers! Good to see most of you are doing as well as can be expected...Nice to be a part of the community, even though I don't post as much as I used to. Visit my sig thread for pr0n.
It's a glorious day, I'm off to the links.