The SVS system is pretty new. Supposed to be nice but size-wise they are more like M2 mains, while the RTi6's are M3-ish and you are looking at M22s which are... well... M22-ish.

SVS is going to be introducing some larger speakers in the future -- those would probably be more comparable to the Polk and Axiom systems you are considering.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8