Given that brass is available, it's a matter of preference IMO. There is a subtle shift in the ratio of portability to power in each of these cals. Sure, the 7WSM is the powerhouse, but launching a 180 Berger at 3000 fps is going to get your attention. In the field, not a lot of difference until the longer ranges.
However, brass for the 7 WSM isn't that easy to find either. As for bullets, the 7MM is an embarrassment of riches.
