I wish I had more oppotunity to listen to more exotic speakers, but here's what I've heard.

Sonus Faber Concerto. Whatta boring sounding speakers. I first heard it with Rotel Pre/Pro. I was in a search of a pairf of BShelf speakers. For that and other reasons, I really wanted these speakers to sound good. It was extremely bland and lifeless. Then I asked my salesman to mate it with Musical Fidelity A3.2 Integrated and CDP. MF made these speakers sound slightly more refined, but I just couldnt pay attention anymore than 5 minutes. I tried them on another occasion but sounded much painful. I ended up spending alot more on B&Ws and couldn't have made a better choice.
I didnt like the sound of B&W Nautlius 805s. When I listend to Signature 805 vs Nautty 805s side by side with Musical Fidelity A3.2s, I thought Nautties sounded very forceful and muffled.

Paradigm Performance Series. I would prefer them over Concerto anyday. Very reasonable priced, but I think it is over-hyped, especially Atom. When I sold my Monitor 5s to my friend for $300, I just gave him CC-170 and Titans(which I upgraded from Atoms).