I was going to wait until my 11's were completely broken in to post about them, but since it sounds like you're in the market for speakers right now, I will do my best to give you the most complete review that I can.
If I were to liken the 11's to a child, they would be like the ugliest baby you've ever seen, that ends up as a beauty queen. When I first plugged them in, I was very disappointed. I knew that there would be a break-in period, and from reading various reviews, I knew that it would be a rather lengthy one at that (one review said approx. 40 hours, and they weren't kidding). All the same, with expectations high, I hooked them up to my 3805, put in a Norah Jones album (at my wife's request... really), and sat back and listened.
It was Norah all right, but the 11's made her sound super-bright and (despite having three 6 & 1/2" inch bass drivers) very hollow. Out of the box, I strongly preferred my old Paradigm Phantoms v.3 to the 11's. We all know that speakers need break-in time, I included this section only because I wanted to stress that the 11's sounded really, really bad out of the box.
Fast forward three days, and approx. 30 hours of use, to right now. After a little tweaking of the eq on the 3805, and some break-in time, I am happy to announce that the 11's I remember from the demo floor are (mostly) back! They sound great at subdued listening levels, but the louder they go, the better they sound.
The bass drivers have really loosened up, and do a really nice job of keeping the lower end very musical. I still wouldn't dream of hooking these up without a sub, but the 11's have added enough detailed bass that I have been able to turn my sub way down (which has made my wife very happy). Their low frequency extension isn't quite as good as the Paradigm Monitor 9's (32 Hz compared to 35 Hz), but I love the punchier sound you get from the 6 & 1/2" inch drivers as compared to the 8 inch drivers on the 9's. I didn't care for the 9's at all (in fact, I had the opportunity to purchase a demo pair of the 9's that were in fantastic shape for $700, and still decided that I liked the 11's better enough to justify spending just under $400 more, but I also have friends who love the 9's so this is more of an individual preference sort of thing).
Two other threads on this site (that I have found) mention how incredible the high frequency driver of the Paradigm Monitor series sounds, and I must admit that I absolutely concur. I am and always have been, (as long as I have been aware of the world of high-er-fi audio, only about 3 years) a big fan of Paradigm. It seems to me that, whereas other speaker companies try to produce more "realistic" type speakers, Paradigm has spent their money on researching how people like speakers to sound. So, maybe Paradigm doesn't make the most accurate speakers around (I think they're very accurate), they are very musical and just sound "right" to me. I think that the 11's are a wonderful example of this rightness of sound, and I enthusiastically recommend them to you.
Limitations of my system:
I am only running these off of the 3805, and I have yet to bi-amp them. Thus, they are only getting a fraction of the power yours will have with the Harmon Kardon amp.
My CD player is absolute trash, and it's digital outputs aren't compatable with the 3805, so I'm using the regular line out with rca cables (sigh). I'm sure this has lowered the quality of the sound I used to evaluate my 11's.
I hope this helps,
Stephen