Titojazz,
I have used and still use AAD, Mapleshade ribbon, JPS Superconductor, Marigo, Reality, in different systems.
There is a basic level of excellence which any fine IC exhibits, and then there is the extra "wow" factor when a certain IC connects certain components and delivers something special.
In comparison to other brands, the AAD's special attribute is transparency and detail retrieval without being too incisive or edgy. It also offers very extended range sound.
The other brands mentioned also provide excellent sound. All are more expensive and one can find certain aspects of their sound delivery to be superior in some way to AAD, which is still the lowest cost great IC I have ever tried. Incidentally, in the next higher price range there is my overall champion, Reality IC at $225 a pair.
There is always a matter of personal taste that is hard to express in words, and it is not possible to convey all the mix and match results due to so many potential combinations of components and wiring. I usually aim to use the same brand to connect all components in the same system.
For example, AAD connects Sound Valves VTP-101i preamp to Cary SLA-70Sig EL34 amp, and connects classic Scott Nixon Anodyne ATAS tube D-A converter to this preamp. My costly NOS tubes depend on the AAD IC's being good enough.
The ability to distinguish subtle effects of various tube changes and other "tweaks" is very high with the AAD, as it is with the Reality.
In another system AAD connects classic Mod Squad phono preamp to Aronov 960i tube integrated amp, and connects EVS Millennium II D-A converter to the Aronov.
Since the AAD is so economical it serves as a baseline of excellence against which others can compete. To my ears, this IC breaks in within the first seven to ten hours, with even more natural sound after about fifty hours of use.
And, it's made in America by a real person to whom you can speak.