Is there a reason other than aesthetic to replace the sub?

I've not heard the M2's, but own M60's and have heard the rest of the classic lineup. I think there is consensus that the M22's are "better" than the M2's, even at low volumes. For that space - especially if you are willing to spring for the upgraded finish - I think that M22's on nice stands would be really great.

I'd get those first and see how strongly you feel about replacing the sub.

I've not heard the EP400. Suggest a call to Axiom with your questions.

Tom, you have a lovely home, and I really enjoy your participation in the forum. Especially since you are always getting and ENJOYING new stuff!

bibere usque ad hilaritatem