I use the PLE. Some points to note:

It's limited to a single CPU (which doesn't bother me at all since I only have 1 anyway).

You can only save files with the ".mp" file extension which can only be read by the PLE, not Complete or Unlimited (just to prevent commercial distribution of stuff you make).

The PLE is based on Maya Complete (so that means it hasn't got all the stuff Unlimited has got).

The watermark is so big that it's almost classified as overkill (but you eventually learn to "see through it"). There's also a watermark that is put on all textures that you make in Maya using the paintbrush tool.

You cannot use plugins, but you can use MEL scripts although the size is limited.

Rendering is limited to 1024x768.

Other than all that it's fully functional and will run fine, providing that your computer can cope!