Recommendation on power amp

Newtoncr, have you tried calling Ayre's corporate offices?  I own an Ayre K-5xe pre-amp, your CD player and a QSB-9 DSD DAC.  Unfortunately, not the MX-R Twenty amps nor your KEF speakers.  

My point is that Ayre's customer support has been excellent in my experience.  They have been helpful in answering several questions and in making some recommendations.  Perhaps they can help you get the amps home for a test.  I would not hesitate to advise them of the response you got from your local dealer.  I agree wholeheartedly with those who have noted that your dealer should be happy to arrange a home demo, particularly given your past purchase of Ayre equipment. 

I did contact them and ask them about compatibility and they said it would sound very good and the preamp and speakers are all compatible.
i agree ayre has the best customer service I have encountered. They are amazing and that’s why I am so interested in their amps.
i didn’t ask them about a home demo but I am just waiting to listen to the krell before I decide on the ayre .
Then all I will need is to find a good deal in the mx-r twenties 

I would suggest auditioning a pair of the BHK 300s.  Really incredible power amps for the money.  They are about 15k, so in the price range.  

And, if you can't swing the $15K, their Stellar line (S300 and M700s) is next best. I have the M700s; finest amps I've ever heard.