I've had mine in the system for about 100 hours now, maybe 150. I'm coming from using the A-L 800VA Dreadnought.
My review has to be tempered a bit 'cause I made another significant change at the same time as the new tranny: I had my amp upgraded to dual mono, with new circuit boards, resistors, transformers, caps, and cap capacity (doubled from 120,000 uf to 240,000).
Both the amp and the new AI-1 sound like they're still improving. The new tranny has taken much longer to burn in the other one, which I felt was pretty much 100% at around 50 hours. What I'm hearing is slightly better imaging side to side, i.e. wider and slightly taller, and a fairly large improvement front to back.
Instruments sound a bit more realistic, more organic. There is a little better resolution in complex passages with instruments, harmony vocals, percussion, keyboards occupy a more definitive place in the soundstage. For example, if a piano is playing deep in the background it's easier to hear. The sound stage also sounds a little larger with instruments and vocals less tied to the speakers and more out in the room.
Instrumental tones sound more pleasant, more like they sound when you're in the same room during a live performance. Female vocals sound smoother with slightly better tone, and a very slight increase in the midrange. This may be why vocals sound more realistic.
The bass is stronger without being overemphasized. I'm pleased about this as my room does not allow for ideal placement of my speakers for the best bass. I can't get them close enough to the back wall.
I also made one other change: new built in cabinet and shelving. While these were built for LP and CD storage and to clean up the living room, improve WAF, etc., they also have reduced a major bass node behind the right speaker. That may have contributed to the improved bass response as well.
As I said, all the improvement in sound quality can't be attributed to the new AI-1, and I don't know how brak it down between the new amp and Dreadought. My best SWAG (sophisticated wild ass guess) is 50-60%.
OK - what have others experienced?