I think some people love Mentor tools because they are extremely flexible, but with this flexibility comes a lot of (IMO) unnecessary details. There are definitely some good features, though.
To be honest, I'm STILL confused by a lot of this. Components have a NAME property and a DEVICE property and a PKG_TYPE property. The DEVICE property maps to the PART TYPE in Layout; PKG_TYPE maps to DECAL in Layout. I can't even remember whether it's NAME or DEVICE that gets used by the Parts Lister (BOM generator). And I can't figure out whether to display the NAME or the DEVICE on the schematic.
There are a number of user's groups out there, Mentor has one and there's one on Yahoo; these can be a big help.
As far as heterogeneous parts, there's plenty of documentation, and none of it makes sense. I was ultimately able to get it to work, but I'll be damned if I can tell you how to do it. Maybe I'm an idiot, but I don't think so. I suggest you take a whack at it and see if you can figure it out.
I will be beta-testing a new package that Mentor is bringing out that lies somewhere between Pads (somewhat expensive) and Expedition (really, really expensive). Their selling point is that it will be 'easy to learn' and 'easy to use'. We'll see.