While I haven't used ACAD2007 for production work yet (company & DOT still standardized on 2006), I've fooled around w/ it at home at it seems OK as far as functionality.  I've ported DWG to DWG14 format & brought that into Hexagon w/o a problem.  However, if you want to do 3D work in ACAD2007, you'll need a pro version of a graphics card - gaming cards won't fly too well.  Certified OpenGL drivers required.

The only bad part in using 2007 is that I loose layer naming.  When I import 3DS into Hexagon, the 3DS layer name becomes the Hexagon object name.  (Hexagon does not use layers, but objects).  ie.  If I have a surface on layer GRAVEL, in Hexagon the gravel surface becomes an object named GRAVEL.

By importing a DWG directly, the object is named "FORM0"(..."FORM1"...and so on).  You have to rename the objects manually.

Hexagon imports: AMAPI (.a3d), Wavefront (.obj), 3DS, DWG14, DXF, Illustrator (*.ai) and generic "all files".

Hexagon exports: Carrara (.car), AMAPI (.a3d), Wavefront (*.obj), STL (?), DWG14 and DXF.  (ACAD2007 imports all forms of DWG.)

FYI - STL file format.  "The .stl or stereolithography format is an ASCII or binary file used in manufacturing. It is a list of the triangular surfaces that describe a computer generated solid model. This is the standard input for most rapid prototyping systems".

As a mention, I've had much better results from DXF2004/2005 than from DXF14/2002.  I think that I surpassed the 3DS limit in one DXF2005 file of 65K faces, but that's something I need to check out further.

The only other downer w/ Hexagon is that you need to move your models from 'project coordinates' to center the model near coords 0,0,0.  I've tried a few models I've had in UTM coordinates and Hexagon (as well as VUE) was very painfull and slow to use, it usable at all.  Once near 0,0,0, it was a snap.  It's a little bit buggy (from what I read in the newsgroups), and support has been transfered to DAZ (from Eovia which sold out) so updates will probably be fewer until DAZ figures out the programming, but I find version 2.1 quite usable for what I do.

Try the demo version, I'm getting kind of addicted to modeling w/ it.  I demoed it to the local AutoDESK reps, and I got a couple of "ACAD2007 does that", but a whole bunch of "ACAD2007 can't do that".