Hi Burr & All....

Basically I come from solidworks. I have been use solidworks for 3 years. Its a powerful solid & surface modeling also. The big different is solidworks have a parametric concept like Michael mentioned before. As I know solidworks is the easiest parametric modeling software.

But today my favourite software is MoI ( because the easy to use workflow & of course MoI is very affordable ).
You can open MoI file directly use solidworks. So it will give you a good combination.

You can find some solidworks video here : http://www.solidworks.com/pages/products/swofficepro/SWOfficePremium_VidVau_fore.html
Also check this link : http://download.rhino3d.com/download.asp?id=rhino-solidworks

OK, that is my opinion ;)