FWIW, I thought the CMH sockets sucked. It takes a lot more force to twist the bulb in or out, and you're grabbing glass. On a hanging reflector assembly. it's asymmetrical which means the right post has to go into the right hole as well.
how is the 2-post socket more efficient? The only advantage would be holding the bulb slightly closer to the true center of the reflector, which is trivial IMO. And the bulb is still unsupported on one end, so it may not center 100%. Centering and the lack of any support wire over the bulb are the reasons why DE is better that mogul. CMH still needs the support wire. But these are only 1 or 2% differences anyway.
we don't need to rely on forums anymore to see what what the cannabis grow industry is doing, or what gear has been developed for it. Just go to the nearest industry convention and talk to the pros. That's what I did. Urban Gro developed their own Philips/PL CMH fixture - they sell it as the ultimate veg lamp. They will tell you that the P.L. Light 1000w NXT 2 fixture is the state-of-the-art cannabis flowering lamp for efficiency and cost of operation. For smaller tents they advise using P.L.'s 600w HPS fixture - NOT dimming a 1000W fixture which I thought was interesting as well. They don't recommend dimming HID bulbs.
can't recommend going to the conferences highly enough! everybody's there, Gavita, all the LED companies, etc. these people are busy working to outfit massive commersh greenhouses in CO and elsewhere:
http://urban-gro.com/grow-light-solutions/cannabis-lighting-products/