Jordan Rudess definitely tries pretty hard to push the envelope in many ways! If you can play as well as Jordan, and the type of synth heavy stuff he does, then PERHAPS you might bump the ceiling. But let's be real... who is doing stuff like his on an arranger?!

As to hitting the ceiling, this problem's audibility varies dramatically with different keyboards. Note stealing algorithms vary from product to product, and can have a big impact. My K2500 only has 48 voices (how things have changed!) but it has incredibly intelligent voice stealing algorithms (and a page where you can SEE the voices being used up) and can often be pushed to the max without actually hearing anything. Short transient samples get reassigned as soon as the sample end is reached, sustaining voices get reassigned in order of level (low level samples layered up can often be dropped in a dense mix with no audibility at all).

But bottom line is, until YOU hear it happening to YOU, not to Jordan Rudess, that's the time to start worrying!