I've owned various Uno and Duo models for the past 8,9 years. Currently have a red Duo, leftover from a Avantgarde/47 Labs system, just sitting there. Have been doing most of my listening with Quads which are part of my second system. I do have an extra Quad CDP-2, an Aleph 3 amp and an Aleph L pre and am thinking about hooking it all up and once again getting the Duo to sing.
To me, it's an absolutely amazing speaker, in the right system, not so much room dependent. Some people would say - get an Uno and then upgrade to a Trio, skip the Duo all together. I had a chance to listen extensively to a Trio as well as an opportunity to buy one but didn't. Duo just did it for me.
Good luck if you decide to purchase. I do think you should take a listen first. Getting the horns to integrate with subs could be frustrating. Nirvana jumpers are a must. In other words, running them full range (bypassing the crossover) you get better results. Hope it helps.
Dragan
TheAudioXchange