I've had the Maxx 3's now for a few weeks now, and went through a significant burn in phase--breaking in a pair of the Berning Quadrature Z mono's at the same time. The 3's sounded too hot and beamy for a while
Having had the Maxx2's for almost four years, the differences designed into the 3's became obvious once burn in was complete (200 hrs or so).
The 3's are significantly improved in the areas of coherence--music sounding fluid with all frequencies in exact harmony. Definitely more speed-- transients stop and start with far greater "suddenness" giving an incredible sense of musical timing. Rhythmic elements in sound literally leap from the speakers, while with the 2's the PRat was more subdued, the pace a bit slowed.
Related to that, dynamic range is w-a-y better. Quiet to loud transitions are more subtle and sinuous, literally wrapping you up in the music and capturing the scale of performances more accurately. Dynamic headroom is also vastly improved with even less noticeable compression at the extremes than the 2's (one of the 2's strengths). This is the area I imagine the X2's are still obviously better in.
Pitch articulation, weight and impact in all frequencies also seems much improved over the Maxx 2, which in my room tended to have some overhang at 60-80Hz and sounded comparatively muted in the upper mid. These Maxx 3's stop on a dime in that range and give you that "thump" to the chest and quiver of the pant leg that was missing with the Maxx 2's.
Sound in general strikes me as more three dimensional in terms of weight, presence, focus and timbrel clarity, where subtle instrument shades are more vivid and 'in front of you'. Although I appreciated the Maxx 2's while I had them, in contrast they sounded a bit fuzzy, sluggish and were nowhere near as good at defining fine transient lines, detail and pitch--the words slurred and sluggish by comparison come to mind. Again, these were fine distinctions but still noticeable in contrast.
Overall a fantastic upgrade affecting and improving the listening experience and the pleasure I derive from listening to music
My comparisons were largely made using both the new 200w Berning Quarature Z monos and ARC 210's with ARC Ref 3 and CD-7.
Love the Desert Silver color.