There's a little more leeway in wind hold with the 7, but most hunters will never see the difference. For example, The 180/7 vs 170/270 will have around 2" difference in wind drift at 500 yards @ 10 mph, which is the difference in hold between a 10 mph wind vs a 12 mph wind. Either will be holding off vitals in those conditions, and I'm of the opinion that if I have to hold off vitals with my wind hold, it's time to get closer or re-position.
The thing that most hunters will be able to differentiate is the recoil - there's a 20%+ increase in recoil with the 7 mag. I've found that portable (say 8 lb or so) 7 Mags aren't much fun to shoot, whereas 270s in the same weight range are a bunch easier to shoot. I've also seen this manifested with a whole bunch of hunters. The 270 guys generally kill stuff without issue. A bunch of the 7 Mag shooters have trouble with the recoil, resulting in missed or wounded game.
