I never experienced any issues playing Space Marine. Is it hardware specific?
the slow motion bug is reported by both nvidia and amd users ...so its not restricted to one card manufacturer, which makes one think that it'd be something other than specific graphics card issue related.
some people say that turning vsync off resolves the issue, but in my experience it just makes it less common (maybe). and since its a random event, i don't even know if turning off vsync even matters ...because sometimes i'll play the game for an hour with vsync turned on before i see it happen.
its just so random ...and some people might not even notice it occuring.
and i don't think its really a small group of people experiencing it. searching google for the issue shows quite a few results (there's also a 10 page thread on Relic's forum about it). so if there's that many people out there that take the time to post about it on the internet, then there's probably a ton more out there that didn't bother to do so.
but anyway, its an issue that's likely to not be resolved. its not game breaking, but rather a small annoyance.
i paid $12 for the game, put about 12 hours into it ...completed single player, and sampled the multiplayer. i got my $12 worth i guess.