Ayre V-Kxe and Thiel 2.4s

Stevecham, with all due respect, he's already unsatisfied with much more power than your currently running with Thiel 2.4's. IMO, it might be enough, then again it might not. Depends the room, and the expectations.
Cal3713, may we ask how much do you comfortably want to spend on amplification?

I'm willing to spend up to $4000 (on agon)... just trying to explore the options and figure out which of those might be worth "auditioning" (i.e., purchasing used and reselling if they don't compare favorably to my current XA-30.5/INT-30A). I'm going to keep it and use its preamp so I can get a good A/B comparison. Getting a cheaper option is simply attractive because it opens up the cash for some other audio purchases... hence the flirtation with the Aleph 2s and the Ayre V-5xe. I'm in Boulder, I wish Ayre would just let me borrow one for audition (I checked and they won't... despite not having any CO dealers).

Stevecham, as Unsound pointed out I do find it surprising that you're getting enough out of the CJ. I'm certainly not in a big room (or a small one for that matter), but my current Pass (the INT-30A... which gives 60 W of class A power into 4 ohms, and probably tops out around 200 wpc) just doesn't control the lower end of the 2.4s. Bass is just all over the place, sometimes it shakes the windows, other times there's just nothing there even when it clearly should be. With the same amp, my Thiel 1.6s actually produced more bass on a couple tracks that I sampled.

Have you considered Krells?

Nope, haven't started to look through the options to learn their lineup yet... but I'll take a look. Any particular models you're a fan of? At one point I was considering Mark Levinson, but the reliability complaints and all the posts about getting the caps replaced turned me off.