Well, since both are implementations of the Modelica standard I would guess they are pretty much the same, though I do not know MapleSim or your problems with it.
It was extremely difficult to model two interacting surfaces -- for example, a wheel rolling on a surface with friction.
MapleSim only implements a subset of the Modelica standard.
if it's like Mathematica vs MATLAB, then it will be much less unpleasant to use. one of the reasons i like Mathematica is the consistent respect for UI/UX