We were using Mechanical Desktop from its 4th version to its 6th version and we had lots of problems when our assemblies got huge. We contacted Autodesk and they advised to buy Inventor. With Inventor we had problems of slow regenerations and finally we decided to switch-over to Pro/E Wildfire and our assemblies are now ok.
BTW Mechanical Desktop is a low end software and as far as I know there is no user forum you are looking for.
I joined my company only very recently. They currently are using MDT and the reason for hiring me is to implement Pro/E here. Since the current bunch is facing a hell a lot of problems with MDT, I thought it might help them if they have something like ProE central and tried to find one. And your reply says it all Israr. Thank you very much and appreciate your time to answer this.
I share one experience with you about the conversion from Mechanical Desktop to Pro/E. If you save Mech. Desktop assembly as an IGES file and you open this in Pro/E as an assembly it works well than any other translation format like STEP etc.
You will get the assembly model tree in Pro/E. What I do after that , I create some saved views like front , top, side etc. and change the units to our standard mmns.
After that I replace parts that need ECO through the standard assembly techniques.
If you need any help in this connection, you'r welcome.