I rarely post on this board. Being an owner of an Exposure pre/power system with some dynaudios, and also a pair of ADM9s i'd like to throw my 2 cents in here...
I got my ADM9s (original 9.0s) from hififorsale.com, i'd read a lot about them and for less than half the r.r.p figured they were worth a punt. Are they good? Yes. Are they perfect-best ever speakers-in the entire world? Nope... But, for the price point they trouce everything else i've heard (e.g my former cambridge audio 640v2 CDP/amp/Epos M5 setup - a whathifi test winner at about the same price new). Admitedly, some of the sounds they make are very very impressive, and to my ear are better than my "passive" system costing about 4 times as much.
Personally, I think it's pros and cons are mostly attributed to their active design... For my PC, I have a system of little known sirocco speakers, which have a similar sonic signature/overall neutral presentation to the ADM9s (albeit much smaller).
http://www.macuser.co.uk/reviews/15235/videologic-sirocco.html
I have met Ashley personally, who was kind enough to give my girlfriend and I a demonstration of the ADM9.1s+sub at his house. Although highly opinionated, he is a genuinely nice and welcoming man who is a great believer in his products. Admittedly though, I do find some of my online findings dubious (e.g darrenwm (who I have conferred with through PM quite a few times) posing as a sicilian man praising AVI products). Shady marketing/shilling aside, the product speaks for itself as a very good one. I do think AVI are shooting themselves in the foot by marketing it best thing ever in hifi, there is far better out there (on the same day I visited Ash I listened to a set of ADAM Tenors at a dealer's house, no contest whatsoever).
On there own, I would not use them as a main system... While punchy with bags of pace/detail, they sound weak on the low-end and struggle to produce a big sound stage with big bass and beats. No doubt this would improve enormously with the sub, but at an extra 800 odd quid I myself cannot justify the extra cost. In comparison, my dynaudio system has a richer larger sound although does not capture the finer sharp upper-details like the ADM9s. Still, they are not going anywhere... They have made a perfect 2nd system which is compact and neat for the living room. Personal qualms aside, I can see how some people are perfectly happy with their performance.