As great as the Antec HCG750 is, I feel like it's basically out of it's price bracket right now. You can pick up the semi modular of the same range (even though it is internally, a totally different unit) for $70 after rebates, the 650W version (which is likely to be sufficient as mentioned) is $60. It's hard to compete with that kind of value for money.
When you step up to the higher prices, there's so many good options in the ~$100-130 bracket if you want something really nice that you can basically pick based on brand preference, retailer preference or whatever gimmick you place value in (massive warranty, efficiency ratings, modular/semi-modular cabling).
EVGA 750G2, Seasonic M12II-750, Seasonic G-750, Rosewill Tacyhon 750, XFX 750XTR, all quality stuff in a very similar price bracket.
If you desperately want a Corsair (as some people seem to) then the AX760 isn't vastly more expensive.
One thing about efficiency and wattage capacity - you don't want to hit the "sweet" spot at 100% load, as A) very few tasks exploit 100% CPU and GPU and B) most PCs spend far more time in idle than they do at load. The exception to this would perhaps be some sort of mining rig where you have a much better idea of your actual usage. Going over capacity for the sake of it, especially when both CPU and graphics tech is generally trending towards efficiency seems like poor advice.