SolidWorks has an educational version too for a low price. I use Solidworks and it's great, but I don't have anything else to really compare. The great thing about CAD now-a-days, the parametric versions anyways, is that you can simulate a lot of things, comes in handy for interference detection. My CNC machine measured identical to my CAD design when completed, it was also *very* close in it's mass calculation too. My new robot, I expect will be the same.
Then there is parametric design, dimensions can inter-relate between parts. Have a problem sourcing a part, then find the closest match, modify the dimensions, rebuild, and watch the other parts adjust to fit...that's of course if you think ahead and design your parts and assemblies properly!
I'm a little new to Solidworks, but "I'm lovin' it!".