Mark Levinson 326s vs Ayre K5xeMP

The 326S is a very good preamp; I owned one for many years.  It's also the best designed preamp in terms of user interface I have ever used or tried.  Having said that, the Ayre KX-R was clearly better and it's not even in the ballpark of the KX-R Twenty.  Given that the KX-5 Twenty reportedly rivals the performance of the original KX-R, I expect that I would prefer it the 326S.  On the other hand, the K-5xe is now a couple of generations old and I don't expect that it will be able to keep up with the 326S.
Irrespective of all that, given your preference, I  expect that you will find that the 326S will be a clear upgrade to what you have now and might even be your preference irrespective of the performance of the KX-5 Twenty.  Be aware that while the 326S still has that typical Levinson house sound it has much less of it compared to earlier products. 

I don't think you can go wrong with the 326S.

@Intim The 326S is not comparable to the KX-R Twenty, it’s not even in the same ballpark as I mentioned earlier. It’s relatively closer to the KX-R but loses to the KX-R in respect of all aspects of performance, what I recall in particular was that the KX-R handily outperformed the 326S in respect of across the board resolution, quickness, midrange openness and treble extension.
My experience in respect of the ML house sound (my first preamp was a Levinson 38) is that it is closed in and dark and sacrifices resolution and speed for a pleasing syrupy vinyl-like sound with a distinct focus on the low end. That type of sound is preferred by a lot of people, particularly those who grew up with vinyl. I have not found it to be reflective of how music sounds in real life but there are many people who disagree with that assertion.