I have tried open-source (octave,mathics) and closed-source (matlab, mathematica, maple) and I can say that nothing comes close to mathematica. In our physics lab, mathematica has truly changed our entire workflow, making it a lot simpler to focus on the real crux of the problem; instead of dawdling around in symbolic manipulation.

I'm not sure what they are using in undergraduate courses, but I think the toolchain by Wolfram has really advanced the way scientists work. It's far from perfect, but it is an amazing tool.