Hello Glenna... *waves* I decided to start a fresh thread, my last reply was buried elsewhere.
Microspot MacDraft PE 5.5 Quartz Edition hands down.
I use Vectorworks 10 by Nemetschek.
When loyal MiniCAD users were constantly complaining that the name MiniCAD gave the wrong impression of its capabilities, they finally broke down when OS X was on the horizon and called it Vectoworks.
Daniel Libeskind won the World Trade Center Design Study competition in New York City..The Freedom Tower.. another happy Vectorworks user. *VBS*
It's everything anybody could want in a CAD program. AutoCAD has nothing better to offer (for me) and I say this with confidence, because I took AutoCAD for 3 years at the local college and have my 3D-modelling diploma from them. I did that because most industry around here is all AutoCAD.
Vectorworks supports .dwg file formats flawlessly, it is not an issue. VectorWorks is my program of choice because of its versatility and comprehensiveness. Another important factor is that it has been around for a long time with a refined interface and good support. It is also a lot of bang for the buck..... even though it is US 1345.00.. that is with Renderworks included. ( I have a LOT more invested if you add up about 10 major upgrades over the last 15 years... hence.. the Mac.)
Vectorworks is available for Windows, and people are happy with that.
I am hearing a lot about SketchUp for Mac OSX. I have a demo of it, but I have yet to take the time to look at it. That's under US$ 500.00
I hope this helps.
Rob