Rs507 we are sorry that you feel that way, and you are basing everything you know about us about what we write on audiogon, it is not the same to actually visit a place and talk to the owners in person.
Caphill we are also big Naim fans we don't have a 500 stack we have a 300 stack with Nac 282/high cap, and a NDX 2/XPS stack sounds pretty amazing, Personally we don't think the OP would have gone that way as Naim tends to work best as a system approach.
Newtoncr, congradulations on the new Ayre amps, we would love to know how in the demo you got the Krell 575 were bright sounding? They are just the opposite, we had our XD 300 off for a few days while redoing our rack and it sounded very flat and a bit harsh when it was just turned on, the next day back to smooth and silky so did you demo these at a dealer or at your home? Where the amplifiers the XD versions? and how long were they warmed up? At this point is it moot as you got the Ayre amps which will have their strengths in resolution over the Krells, but are way more expensive with less volume capability.
Also sorry to hear about your "dealer" that wouldn't lend you a set of amps, that seems particularly rude considering you have purchased from him before.
Good luck and let us know how the new amps work out.
Dave and Troy
Audio Doctor NJ