I completed an audition with respect to the T748 and the A1020 ... the A820 had been sold, and was no longer available, so I chose to audition against the A1020, as a frame of reference.
Since this is a PSB speaker thread, the front speakers used were Image T6s, and Image B6s for the rear, center was also a PSB, but not Image series, and really looks high end, not sure if it was the Synchrony. Subwoofer was a PSB SubSeries 300.
Overall, the T748's sound has more weight, and actually sounds louder than the A1020. The sound was "warmer", and had more punch.
The good thing about the A1020 was the very good surround steering, the way the A1020 steered the sound effects from one corner to the diagonally opposite corner was really good, but the sound was a bit thin, and not as exciting as the T748. For watching movies, I prefer a more dynamic sound.
The fact that the A1020 was about 1.5x more expensive than the T748, and the fact that I did not need the features present in the A1020, resulted in me putting my money down for the T748. I have a HTPC, which takes care of all the "smart" stuff.
I heard the A820 is sometimes selected over the T748 due to connectivity to the internet and Apple devices.
I listened to stereo on the T748, and the sound is good, but not as good as dedicated hi-fi (would not expect it to, or maybe it was the fact that a BluRay player was used as source).
Thanks for the detailed update. Did you pull the trigger on the 748 or looking to find a 820 to audition?