Stan's user here...
I've got Stan's Flows with Ravens (2.0s) on my '08 Stumpie FSR 29er with I9 hubs and I feel they're relatively light but strong. The I9 hubs are amazing, but I find their aluminum spokes break far too frequently and their customer service isn't as responsive as with some other companies.
My new 29er SS has white Stan's Arch rims with King hubs and the "angry bee" sound is awesome--like a buzz saw! King hubs are so well made, (IMHO) less finicky, and easily rebuildable and adjusted that they're worth the SLIGHT weight penalty. These wheels feel very reponsive to me. I've also got Stan's Ravens on these wheels, but 2.2s.
Considering how much I love Specialized products, I doubt you'll go wrong with Roval wheels. However, I'm a real fan of Stan's No Tubes products and feel their wheels are also a great value.
Good luck with your decision.