my specs are i7 3770k, 2*4gb mushkin @2133 (1.65V) hd5770. 1wd blue 500gb and 1 wd green 1tb. motherboard is gigabyte z77x ud5h.
I know it's not fair, but it will never be. Not even with two products from the same make and model. I know silent pro, a friend owns an M700 and we crossfired his 5770 with mine just to see how it works, and the psu did its job flawlessly.
Although the price of the hale82 made me doubt about getting the silent pro. My guess is that nzxt's is better quality, (I know this is stupid) but silent pro has bigger heatsinks
I'm buying form local retailers here in Argentina. hale82 750 is around 200 US dollars (plus shipping, which would be around 10 dollars more) where M600 is 230 dollars.
there's little difference between those prices, also I can get hale82 650w version for 180 dollars (plus shipping) which in terms of power is a little close to silent pro. also with the difference I was thinking of buying a few fans for the case.
sound isn't much of an issue since my case has bottom-mounted psu.