I have loaded and hunted with 7mm wsm and the 7mm saum, for me there is no differance in shooting / hunting. They both work GREAT.
The 7mm saum is easier to reload though. The case fits the shell holser better and seems to go through the dies smoother (with less effort). Perhaps this is due to my 7 saum is in a custom barrel and all, but still ...
Side notes: All of my 7 saum brass is 300 saum necked down to 7mm. The 7 wsm brass was over the counter Winchester headstamp 7mm wsm.
Usually I take my Browning 7 saum to go hunting because it is more all-weather than my other big game rifles. In snow, rain, or whatever, it refuses to rust. That is so cool.
So, saum or wsm; just do it. There are no bad choices here.