Does anybody have any metrics to compare the performance between running a windows 7 Boot Camp partition under Fusion vs. running as a standalone VM? If the performance is better, I would like to get rid of the BC partition, but if there is no real plus to doing this, I do like the flexibiilty to be able to boot into BC if I really really need the performance (graphics, etc).
I'm not aware of any public comparisons. I would expect disk performance and not having to worry about potential activation problems to be the only major differences.
If I were to change to standalone, would you recommend importing the BC partition, or starting from scratch with a new VM?
Starting from scratch is always better (but is not as convenient). Any time you import a physical machine (via our migration assistant, Boot Camp import, Converter, etc.), you're left with cruft from the old system that at best wastes space and at worst actively gets in the way.
