As someone who has used AutoDesk Inventor, PTC Elements/Pro, and Solidworks in an engineering setting, they are all pretty much the same toolset but with the buttons rearranged. If you want to use CAD software, though, what really matters most is whether you can find a guide that is well-written on how to use CAD software for things. You may, in fact, want to take a course at the local community college. Whatever software they use, you can then buy and be at least moderately experienced with it.
My college uses http://www.amazon.com/Introduction-Solid-Modeling-Using-SolidWorks/dp/0073522694 this book and it's pretty well-written, if you would rather avoid having to take a course. Solidworks is very capable of doing anything a hobbyist might want to and more.
Definitely mod up, he is right because it seems to me that ALL main stream 3D CAD software (solid edge, solid works, autodesk inventor, etc etc etc) are all basically the same, just the arrangement of the GUI is different. The nuts and bolts are the same.
Also, the commercial big name packages are a LOT easier to use than the freebies. It's like the difference between Adobe Premier and Vegas Video. One is intuitive, and the other is like trying to eat soup with a hammer. "You're gonna have a bad time"
Perhaps a tour through TPB would be in order? Oh, wait, that's just a joke I would never advocate piracy.