The situation I'm working with is producing a basic model in sketchup with no joinery details, then sending it along to an engineer who is working in CAD for further frame design.
I've been modeling with groups only in the design stage, then when I am ready to detail the connections I will convert the groups into components.
After engineering I would be importing a CAD file to sketchup.
One problem I've found when converting CAD to skp is that the scale jumps up by a factor of 12. Not a big deal, as the model is easy to resize, but curious if this is a common problem in going from CAD to sketchup.
-btw nice website bmike.