The first thing I think of is how much time I've wasted trying to bend AutoCAD 2000, 2004, 2007, 2010, and 2011 into doing what SolidWorks was born to do.
The second thing I notice is the incredible, whopping, unbelievable speed increase of SW over AC (all versions), all other things left as equal as possible.
The third thing I notice is 1/10th the memory consumed by SW vs AC (all other things left as equal as possible).
Fourth, I'm blown away by the shocking speed of possible changes to the model. Fifth, I'm blown away by the dramatically increased interconnection and features - especially "Assemblies".
I should go on but won't. When what took us two years to accomplish using AC was replaced --literally, and without exaggeration-- in two days in SW, that kind of difference is criminal.
I wish we had found SW years ago. I'd be a younger man.