In my opinion, anything from Ayre is a quality product that will be serviced whether you are the original owner or second or third. And, anything with the Diamond circuit is killer.
I own the MX-R/KX-R (non Twenty) and find them to be very capable in my system. When a cap blew on the MX-R, Ayre had me ship it back for repair. It took 2 weeks and they charged me very little-including return shipping.
Same thing for a Codex that shorted somehow.
The AX-7e is rated at 60wpc. The V-5xe is 150wpc.
You mention 20 ohms- did you mean 2 ohms.
In any case, I would call or email Ayre. Ryan or Ariel would be the best people to answer your question.
Bob