Vandersteen 5A vs Mcintosh XRT28

I've had the 5A's for almost a year and while I do love their sound I'm thinking of trying something different ;) I heard the XRT28's at RMAF in 2007 or 2006 - don't remember exactly which and I really liked them. Do you guys think I'm going to regret it? I can do a trade with a dealer on the speakers. My Cary 211 amps are rated at 110wpc and I feel that may not be enough drive the 28's properly. My room is 15x23x14 with an open back. I like that the 5A's have 400wpc sub amps - the 28's do not and are about the same efficiency(88). Just looking for some opinions - I know this is an open ended question that only hearing both side by side would answer but that isn't possible.
Thanks in advance ;)
Tony