Thanks for the replies Murph.

The Ax-5s are pretty big. They're old but still have a 1" tweeter, 5 1/4" woofer, and a 10" rear-ported sub in each and sound pretty decent. Since they're floor sitting towers, would they still be ok height-wise as surrounds? It's pretty enticing to think they could be moved there. I guess I'd place my AX-2 bookshelves in the rear and the m22tis to the front with a sub...

This is really a nice problem to be in!

Pioneer 1018, Optoma HD65, LG BH200
Axiom m22ti
Mirage OM-C2
Axiom AX-5
Axiom AX-2