http://bugs.winehq.org/show_bug.cgi?id=10749
--- Comment #15 from Valeriy Malov jazzvoid@gmail.com 2009-08-13 14:38:39 --- I think major slowdown was fixed long time ago by Alexander's commit (just removing console spam?), still the software emulation is in use and it's not affecting playability that hard. Instead, some slowdown (maybe this bug. maybe not) breaks mouse wrapping.
Seems that the bug can be marked as fixed for now, until xinput2 will fix mouse wrapping.