I used to buy only Mausers with my C&R. Swede, Persian, Yugo, Czech, German, etc. But I started reading about the Mosins and they slowly grew on me. The Finns turned them into truly world-class weapons. 1.5 MOA at 100 yards open sights is no joke.
I find the Mosins are more fun to collect. Each of them has been re-arsenalled and reworked so many times that each has much more history behind it than any Mauser. Most of the Mosin tangs have a dozen or more arsenal stamps. They have been converted into carbines, maybe twice. It's amazing how many incarnations and theaters of conflict one 91/30 could have gone thru. The mosins are cheap (~$60-$200), shoot cheap ammo, and are generally very reliable.
Mausers have smoother, more refined actions, but Mosins are cheaper and have a more interesting history for each one. Some small Mosin parts are really soft though. I've broken the barrel band springs on my M44 before.