Has anyone compared the Ayre KX-5 and the Moon 740-P

The Ayre is going to be brighter.  Ayre overall is slightly forward of neutral.  Great circuit.  Wonderful imaging.  Completely silent.  A cliche I suppose but Ayre has "blacker blacks" than anybody.  The volume control on this unit is very good.  

I have not heard that specific Simaudio unit.  Overall, Simaudio's house sound is a hair more neutral than Ayre.  More than competent.  Good imaging.  Lots of detail.  I find Simaudio's sound boring in the sense that nothing stands out in any way.  That is probably the worst way to compliment a product I can think of, but you get my point.  

The rest is probably not what you are going to want to hear...

Both are going to offer tighter bass and crisper sound at the expense of imaging and staging.  IMO...Neither is a step forward.  In fact, I would argue both are a small step backward in the sense that what you gain in precision will not offset what you lose in imaging.  If fairness, I am an imaging junky so....  They will both offer much lower maintenance. 

I feel like both the Ayre and the Simaudio are at the high end of very, very, good while your ARC is at the low end of truly great.  My expectation is that you will be just a hair disappointed with both compared to your ARC.  

Verdantaudio, thank you for your response. I will not argue that I will miss the quality of sound that I have grown to love with the Ref5. But I have weighed these losses vs the other benefits I feel I will gain by eliminating the Tubes. I have accepted that and want to retain as much of that sound as I move forward in my transition.
I had kinda wondered if Sim would present a more analytical sterile sound. I had an Anthem Statement processor and when the Ref was back at AR for repair, I used it as my pre and just couldn’t listen to it. I wondered if it is more of a Canadian approach designed from an engineering efficiency approach rather than musical.
I have always liked Ayre and do plan to bring one in for a week to really get a feel for it. My thought on the Sim is the option to add an outboard power supply down the road.

again Thank you for your response 
Theo

arc will image broader taller deeper, more bloom in mids midbass less in the deep bass, treble and transients will more relaxed

I wouldn't say that about Ayre at all, but it also depends on which piece it is.

For example, I demoed an ARC Ref 6 against a KX-R Twenty and it took me less than two minutes to give the Ayre the win in terms of soundstage width and depth.

The ARC sounded very good but the Ayre was much better.