Bifcake
I should declare up front that I have an 861 - so you know what I'm going to reccommend
Your choice of course depends on what you want from your music. I listen to >90% "classical" from renaissance to contemporary, majoring on 1850-1950, but with a bit of jazz and rock thrown in from time to time. I also prefer a clear but slightly bassy sound (my favoured position in a concert hall is about 15' behind the conductor, and about 4' to his/her right).
I originally had no intention to go this far up market, but when I started noticing a few things about my Meridian 508.24 I wasn't too keen on I auditioned a few things that may give an upgrade.
I had a head-to-head here of the Meridian vs the NuVista 3D and a Krell (CD300 or somthing like that - can't exactly remember the model number). The NuVista sounded absolutely beautiful, but glossed over quite a lot of detail (e.g. words didn't really come through). Krell has a rep over here of being brash, in-yer-face, unsubtle (i.e. a typical yank

). I have to say I didn't find it as bad as the rep, but it didn't really invite me into the music.
Next I heard a Chord DAC64 (driven by the Meridian) and Wadia 301. Absolutely no contest - Wadia won hands down. The Chord gave a bit more warmth than the Meridian alone, but sounded rather artificial to me. The Wadia had life and a solidity and reality to the sound that I fell in love with immediately. Only problem was disastrous ergonomics.
I also compared the 301 against the Resolution Audio Opus 21. I think the RA is an absolute disaster for classical - harsh and tuneless - but does have super clarity and soundstage that would probably suit the techo-types among us. I also tried a Tube Technology something (about 3k), but that was everything bad about the valve stereotype (music wading through honey and treacle).
Having fallen for the Wadia sound big time, I then got a 2nd hand 860 and got it upgraded to 861 spec. I didn't really listen long to its 860 incarnation, but was actually quite unimpressed - the life/bounce and solidity was missing - but the 861 upgrade (the 301 electronics contain a trimmed down version of the 860->861 developments) completely transformed it.
Bearing in mind Merlin's comments, you may also be interested that while auditioning speakers, I took the 861 around to someone selling B&W 805sigs (which I didn't like - but then then there are very few standmounts I have liked) - who also had an AA Capitole II. After it was clear I wasn't going for the 805s, he listened to the 861 for about 30 secs, then turned to me and said "Now I'm
really pissed off" - having not got a sale, he now wanted to get rid of the AA and get the 861 instead.
I've not compared directly against the AR, ML or Cary - although I did hear a full Cary system once and felt it a bit sleepy.
Another make that gets good reviews are Electrocompaniet. I've not heard their EMC1 mkII (and you may have problems finding one in USA), but it's supposed to address the sleepy/soft rep (i.e. the bad side of the vinyl stereotype) of the Mk1 version.
I would probably agree with Merlin's characterisation of the Wadia sound - beefy, bouncy, lively, detailed, but above all a sense of "presence". I've not heard anything that draws me more into the performance. I think it does an even better job of rock than classical. It doesn't have quite the enormous soundstage of e.g. the Meridian, but it's still pretty good. Of course the Naimees hate it (even though it's black), but they're welcome to their own :JPS:. There are several users on Audio Asylum who swear by it, particuarly after modification by Great Northern Sounds (which is supposed to address that) - and WM here has made significant changes to Wadia kit with his tinkering (although I can't remember what the verdict was on the surgery applied to his brother-in-law's 861). I've not done any mods, but I (and clearly others) think it sounds pretty wonderful even without the mods. GNS may also help with locating a 2nd hand one.
But of course...YMMV!