I can compare the 9LS to the L880/2. They're both set up in my living room now. (Actually, I modified the crossovers so the ARs are 9LSi - an easy and definite improvement). I've been comparing them on my Pioneer SX-D7000 (120wpc) at the short end of a 18 x 12 room.
The ARs go deeper - pretty significantly. The bass from these speakers is simply not to be missed. The bass in the ADS is very very tight, with a neat growly quality, but the last octave of the really deep stuff on organ music or ELP "Lucky Man" is just a tramsient unless you hear it from the ARs. So, slightly tighter with the ADS, deeper with the ARs.
The midrange is a tossup. ADS uses a 2" dome, AR a 8" cone + 2" dome. In the unimproved form, the midrange is hot on the ARs. Male voice range is just way off balance. Improved - they do just about the same thing, with a little rolloff at the upper end of the ARs.
High end - the ARs roll off, and will sound veiled at first. When you settle in to them, they're just easy to listen to. The ADS are very accurate - almost to the point of being clinical - if that makes any sense. I think I'd like the highs in the ARs to match the ADS - I'm eventually going to recap to see if that gets em there.
Imaging - both present a very cohesive image is placed correctly. They have very similar driver complement and placement on about the same width baffle.
So summary - both are dome speakers, the ARs are an East Coast speaker with slightly rolled off highs and insane low bass, the ADS have crisp accurate highs and tight tight bass.
Hope that helps. If you decide you don't like the ARs, please let me know.