I've always thought the Connect:Amp was a turd, but have been impressed with the new AMP.  I've had one of the AMPs since summer for Beta testing.  It's a pre-production unit, but I don't think the hardware was changed.

My experience is sound quality of AMP over the old Connect:Amp is night and day difference with the new AMP clearly better.  I've done some A/B/C testing with the new AMP compared to the old Connect:Amp and also Marantz SR6012 and prefer the AMP (Marantz comes in as a close second and the old Connect:Amp isn't in the same league).

When I swapped from a Connect:Amp to the new AMP even my wife who doesn't give a shit about any of this immediately commented on how much better it sounded when playing music.

Not sure what's going on with those of you reporting that you can't get enough volume out of the new AMP.  Mine is in our Living Room connected to a pair of bookshelf speakers and we use it every day for TV & music with volume settings that are usually between 20-35%.

I just did a test by grouping our Living Room and Back Yard.  The back yard has an original Connect:Amp powering a pair of outdoor speakers, and the Living Room has the new AMP powering a pair of bookshelf speakers.  It's not a perfect comparison because of the different speakers, but with both zones set to 50%, the new AMP has noticeably more output.