Well as everyone knows money does not buy happiness.
In putting together a system, there has to be synergy and you just can't replace one component with another and expect it to work just fine, especially with high end speakers and amps. I think he bought the Be-10 because it also has beryllium tweeters like the JB Labs Alto, so I would suggest finding out which amp is best for this Usher, which is new, replacing the ML which is dated.
The other simpler alternative is to introduce the Tact (maybe he can try yours) into his system. This will compensate for the room and to some extent smoothen any incompatibilties in the system. He may be able use it to touch up the system to sound just the way he (you) like it.
