Our university recently switched from Mathematica to Maple, and I can't say I'm sorry. Though Mathematica gets most of the things done, I prefer the more intuitive way Maple works. I'm anxiously waiting for the Mac OS X version, but I've found no problems running Maple 7 in Classic. The only thing I regret is the confusion surrounding linear algebra (one of two rather incompatible packages are needed: "linalg" and "LinearAlgebra") -- this is a pity. Overall: recommendable.