Go 4 it if u need 2, it makes adjusting the beat and getting it spot on much harder in the positive section, but in the negative section it makes it easier as there is less minus adjustment, I think. I say I think cos I did it about 4 years ago 2 mine, so can't really remember that well, but found that it was more hassle than it's worth, setting a mix takes longer and much more fiddling about, so I adjusted them back as near as I could get 2 the original spec. Anyways, most tunes sound stoopid sped up too much.