Ayre K-3X or Aesthetix Calypso? with a

I have a FPB300c through which I have had an extended opportunity to compare an Ayre K5xe and a Calypso with standard tubes. I preferred and ended up buying a Calypso. The K5x sounded like a more refined (less harsh/more tube like) version of the Krell KRC-HR I had before but the Calypso was more musical, much warmer, and just drew you more into the music. Initially, I thought the soundstage of the Calypso was less wide than the KRC but this changed with better tubes.
Hope this helps.

I'm a biased fan of the Calypso. With the right NOS tubes, this preamp stands out.

Haven't heard the Ayre or the new Calypso. Either Modwright linestage, however, is better than the original Calypso: more extended and neutral with better control, transparency and soundstaging. My prejudice is for a tube linestage with a SS amp.