Well i was watching the evo 2011 stream today and during a certain match, i cant remember who was playing, the random stage select had chosen kratos' stage.
Well the commentators (arisa and ultradavid) said that the kratos stage was unplayable on a competitive level
Yeah, it's because the screen shakes--I cannot stand that stage for that exact reason. Also, some tournaments ban the Street stage because of the cars blocking the players view. Both of these are cool for the feel of being in the stages, but are not appropriate for competitive play.
the screen shakes whilst that giant lady is smashing up the background. it really doesnt bother me much, tbh, and if i can perform combos with the screen shaking the tournament players ought to be able to as well. but at tournament level there simply cannot be any variables between matches.