I have this exact setup (60s and vp100), and I was worried about the vp100 being undersized too. I think it sounds great, and I have no plans to change.

It's pretty much along the same lines of what you've seen posted, but here's what I heard when I asked if the 100 was too small for the 60s.
http://www.axiomaudio.com/boards/ubbthreads.php?ubb=showflat&Number=198723#Post198723

Also, I checked the trade-up program, and it looks like you're only out about $30 if you decide to switch within a year.