Have you tried the center in different positions just in case it is a positioning issue with the Athena?
I guess we could have all said we have have heard a difference and sold you an Axiom system but you seemed happy with the Athenas so why try to sell you more. OTH, the few Athenas I have heard are nice sounding but do lack the extra detail/forwardness of my Axioms.
Since it is only one speaker you are looking at, the return shipping cost for a VP100/150 wouldn't be much if you end up not liking it and we would all benefit from a review of the comparison.
