Mosin is known to have trouble feeding, due to the rimmed case. There are fixes, but it is a known problem.
Mosin is known to have accuracy issues if the bayonet is not mounted and extended (with some models)
Mauser.... I don't know of any "known" issues with it. It feeds cartridges like butter, no matter how energetically (or not) that the bolt is cycled...and accuracy is not dependent on any accessories being mounted or not..
Mosins have trouble feeding. A properly functioning Mosin feeds better than a Mauser (every case is in exactly the same position, before being pushed into the chamber).
Mauser accuracy is dependent upon proper inletting for the stepped barrel. Take any shortcuts, and the POI starts to walk, as the barrel heats up.
And feeding can take a quick turn for the worse, when dirt gets into the magazine box (usually causing more issues when feeding from the left, than the right).
Mausers should also be considered incapable of being single-loaded with any reasonable speed. The claw extractor was not designed to snap over cartridge rims, with any regularity. As such, cartridges must be single-loaded into the magazine. The Mosin does not suffer from the same issue.
They're both great rifles, in their own right. ...But they're very different rifles, designed for very different usage and maintenance.