I've used the industrial MH bulbs from Grainger and I have also used the special 10k spectrum MH bulbs from Plantmax. In my opinion, one works as well as the other. Really, I am done with MH experiments and have gone back to HPS for good. The whole "one bulb for veg, one bulb for flower" thing is a bunch of crap invented by vendors to sell you two bulbs when you really only need one.
Also, HPS is easier on the eyes and I like to watch my plants grow.
Ive heard from a few experienced growers, who's opinions I trust, that if you use air cooled hoods, have good ventilation & get the light as close as possible, HPS will produce excellent results, there's just no denying it, however if you took the same exact setup but used MH, you would get tighter node spacing, (slightly) faster growth & tighter buds at the loss of some yield, like I said, the people Ive heard this from know what their talking about so its hard not to heed their advice. Ive also heard MH produces slightly more potent bud however I believe genetics plays a more important role in that.
So based on results from the growing Ive done, the grows Ive had a hand in and the advice from people I know and trust, the best way to grow IMHO is either, MH for veg & HPS for flower or CMH+HPS for both, personally I'll be using CMH+HPS as the results Ive seen are practically unmatched. The whole point behind using MH for veg & HPS for flower is to replicate the plants natural environment throughout the seasons. During spring and into summer (depending on geographical location) the light from the sun hits the earth in such a way that it produces a more full spectrum, approx. 5000K (blues/greens), the days are longer so the plant stays in a vegetative stage focusing on stem, leaf and branch development, once fall & winter come, again the light from the sun hits the earth at a different angle producing a different spectrum, approx. 3000K (Red/yellow), the days get shorter/nights longer so the plant starts the flowering cycle.
We already know without a doubt that the sun can't be beat when it comes to growing plants, with results so irrefutable don't you think it would be wise to try and replicate the process in which those results were achieved? I mean if plants in nature get a full spectrum during veg season and a lower red spectrum during flowering season (and we already know nature does it best) it just seems logical to use a mixed spectrum IMHO.