I have a 2'x3' area for vegitative growth that also houses some food. I use the CMH lamp in a 400w HPS setup because it gives me a nice even spectrum and lower operating temperature. The difference in the quality of my growth is noticeable. I have no experience with flowering under the CMH yet, but as I'm going for quality over quantity I believe the CMH will exceed my expectations.
My ladies are nice and green with solid growth. They are short and bushy, which is ideal for vertical space constraints. The "stockyness" is from the CMH, because when I grew this straing under HPS for veg they were stretching, even when I had them close to the lamp. Heat was also out of control with the HPS because I have no fans in my space. The CMH has cured this, but my grow area is rather open because it is on 18/6 and I'm not worried about light leaks on veg.
In the new year I will know what the CMH behaves like in a cabnet, as that is how I will setup my flowering area.
The cmh throws off a very crisp, almost natural white light with a barely noticeable bias to the red, I would say but almost non-existant. It is rated at 4000k, 34,800 initial lumens, but don't let that scare you. The way the plants behave under it is amazing with almost no stretch, even with one plant being 3' away from the lamp verses 1.5' away for the others. The only reason i still have my HPS lamp on the shelf is in case of an emergency and I need light for the ladies.
I'm using SOG with Supreme Skunk, promix and hydroton expanded clay thingies. 13cm x 13 cm square planters. I'm hoping to keep my plants under 3' tall when flowering is complete. I would take some pictures, but my iphone doesn't like that bright light.