I don't own or shoot on a regular bssis either one. I don't need the extra power they provide.
I was at one point interested in long range shooting. The lack of range length and practicality postponed the whole deal, but from a cummulative knowledge gathering, I compiled many factors that played a role in my choice and decided that 7mm is better for hunting applications.
300 WM gets an advantage only because of the large military applications and their subsequent developement.
If I was to buy one now, the cost factor would lead me to the 300, as I reload for the 308 and the bullets are there already, but no other reason.
the 7 mm is what I recommend.