I have a pair of AV-6.5W's in my kitchen for stereo use and am quite happy with them, all things considered. The dealer I bought them from also carried Paradigm CS-160 in-walls. They were all mounted in the same wall in their demo room and I judged the sound quality from the Ambientis to be superior (They didn't have other Ambienti models mounted, so I couldn't directly compare all the models you listed). I have difficulty putting my judgement of sound quality into words, but to my ear, the Ambientis had a deeper bass response and sound staging was better. They also cost about 50% more than the Paradigms. But, I was willing to pony up the extra cash for what I judged to be a better speaker. In the end, "sound quality" is quite subjective and it would be dishonest of me to guarantee that you will like any of the speakers you listed. You have to listen to them yourself.
Does your dealer have all the models in your list mounted in a demonstration room? That would be the only way to compare sound quality directly. Since they are all from the same model range, I would guess - and this is only a guess - that the sound quality would be quite similar. The only appreciable difference would probably be the bass response as a consequence of the different mid-range/woofer sizes. The speakers' specifications, as listed on Angstrom's website, include a frequency response range, but don't indicate a tolerance, so it's difficult to say what a realistic frequency response is for each speaker.
Hope this helps!