Been awhile since I did 3D in Autocad.
Need lots of ram, lots of virtual ram but I think that's handled by XP nowadays.
Used solid models for the most part because it was easier to subtract stuff and then union other stuff together.
I know I used 4 views at a time. One for plan, side and front views and one for an iso or 3d view. Used the UCS a lot (especially for funky odd angled stuff). Oh, started on R12 and have not really unlearn that way of modeling.
I've been trying out Revit and it seems pretty cool except when it comes to certain kind of forms or roofs. I just bought a book to figure that one out. Know how to get it done in autocad but not revit. Some people think Revit is more intuitive but after autocad and max, I think the old way of doing things can actually trip you up in a new program.
You can download a demo of Revit to play around with.
It used to be fun in college and for the first few years working. Then I didn't have to for a long time. Nowadays I just stress out thinking about it and whether I should be switching from acad to revit. You hear so many different views..... Plus if I make the wrong decision, it's my own money I'm burning now.