I'm pretty well aware of what IV can do, I've been using it since build 157. We were 1 of the first 10 alpha sites for IV. I really like the product developers and consider many of the guys to be personal friends after working with them since 1998.
I've used Pro/E, SolidDesigner, MDT, IV, and to some extent SW. Pro/E was my favorite to use but my least favorite to deal with as an administrator. Too many people just can't be productive with Pro/E. Recently we purchased a competitor and with that came SW licenses and a large SW database. I am familiar with SW up to release 2001+, not a guru by any means but I can function with it.
Autodesk dropped support for all IV files that haven't been migrated to release 5.3 or later. This is a moving target, support for anything older than R6 is on the horizon. I have a large amount of data that won't migrate (always drawings). Autodesk marketing has decided that is my problem not theirs. That has prompted me to look elsewhere.
In a nutshell SW and IV have similar functionality, but IV is always easier to use and SW is always more capable and stable. Both will do the job, I'm just trying to "discover" if you will some of the things about SW that you come to appreciate. Also, when they say the program has feature X does that feature really add productivity or just allow them to check of a feature on a list.
Some examples of IV functionality that I appreciate after using other packages would be:
Equations: IV is better than SW hands down.
Graphics: SW is an eyesore compared to IV. I don't know if it is anti-aliasing settings or what but IV is better.
DOF and dragging: SW in the versions I have used doesn't allow you to drag parts along unconstrained paths.
Trail Lines: In the SW versions I have used it doesn't automatically create trail lines for you. Not that I really like IV presentations because I don't but the trail lines are superior to older versions of SW.
2D sketches: In general IV has a very nice 2D sketch system. My biggest beef would either be the invalid axis/origin issues or the bugs regarding constraints to projected geometry that can't be deleted because they don't show up in the "show constraints" tool. Be that as it may, I think IV has one of the best 2D sketch tools I have used.
Zebra stripes: I have no idea how the rest of the world functions without this. OK never mind that was a joke