I've had the new firmware for my 8Ks for about a fortnight, but wanted to try a range of music to make a more balanced judgement. Both initial impressions and longer term listening are positive. Contrary to some suggestions that there might be no audible change to 8000.2s, I can confirm that the Mk2s also benefit from the new bass alignment, at least to my ears.

What I find is that the bass is tighter and more controlled and the mid and top has also benefitted, being more open and musical. One thing that no-one else has mentioned so far is that I found the 8Ks (and the 7K2s) on close-miked vocals with a few singers when they are belting could tend to be a little shrill. That tendency is somewhat reduced now so I would say that the upper mid-range is sweeter. Overall music seems more together and coherent. These are not vast differences but noticeable. Or I might be benefitting from a placebo effect, but in any case they sound wonderful, so well done M.

MC200, Twinstore, 808v6/ID41 -> DSP8000SE (+ SB Touch, Sony BDP-3300, SKYHD, legacy cassette player)
2nd system: MC200 analogue out, Linn LP12, SB3 -> Quad 34 -> M60 rosewood
F80 (Rubino Micallizzato)
F80 (Rosso Corsa)