For reference GM uses NX (formerly unigraphics) which allows users to combine both parametric and direct modeling techniques as they see fit. It does combine, as speculated, a variety of embedded engineering tools including motion & a couple of varieties of strength analysis. Some of the tools are part of the base NX package, others, like the basic FEA package are third party softwares that retain full associativity with the base moodel. Designspace by Ansys is used for upfront analysis (order of magnitude results) by introductory users. It is very similar to the Inventor FEA, probably because it is made by the same people. There are even some homegrown tools that are created for specific things like driveline planning, suspension set-up, and occupant packaging.
One thing thing I have noticed is that for most people learning the second software is far more difficult than the first and they forever prefer the one they learned first. (I'm generalizing here, no flames required.) People seem to learn either direct modeling or parametrics first and then try to learn the other for thier second package and have difficulties because they are, well, different. Then they try to bin the packages into better or worse categories instead of acknowledging that they are just different and suited to different things.
In general, direct models, like AutoCAD ,allow you to get the first pass done quicker than parametrics, like inventor (especially if the used tried to capture 'design intent'). However, parametrics will generally get you to the second draft faster if the design intent remains consistent. If the design intent changes, through a major geometry change, then direct modeling probably goes back to winning.
It's all about knowing you process
, designing it to your best benefit, and picking software that supports it.