I have been researching the WSM's myself since I'm looking into getting a new hunting pistol. I've decided to go with the conventional calibers instead for the following reasons:

Ammo is more expensive and harder to find. Also, the barrel will wear out a bit faster due to the higher pressures.

The advantage is that they gain a little extra velocity.

I thought about it and I don't see the WSM's as having much of an advantage over the standard loads. But, if you like short actions or want something new, then it may be just what you want.

A 7mm WSM would make a fine deer gun, but so would 7mm RM. It's a matter of what will suit you best.