It seems way too inconsistent to have such an extreme change in slider velocity that can happen any time on any map. A perfect example is WWW getting -1 on the new dragonforce map right at the point where 1 slider suddenly decreases speed by what seems like -90%. I know you can play it again and remember where it does it, but that messes up sightread plays and just overall seems out of place for a rhythm game. What would make sense is only allowing a certain percent change from 1 slider to another. Maybe 10% change, then with another slider another 10% maximum increase/decrease of velocity. This is done in Image Material, where you actually have chance to slow done as each slider gets slower bit by bit.