For $650 speakers, you can't ask for much more. If I were you, I would just try another amp that is higher end from a company who gives trial periods, or maybe borrow another amp from a friend to try if you have one who has multiples. After seeing as many reviews on those speakers as I have, they are supposed to sound better the higher grade equipment you have.
I agree with Jasonbourne 52 not to bridge in mono for the reasons given.