I have Dynaudio Audience 82's up front, and Audience 40's in the back.
Amplification provided by Audio Refinement Pre 2 DSP + Parasound amps.
I absolutely love the sound! 8)
The 82's are the first pair of speakers that sound so good that I don't feel the need to upgrade.
I have a 10" Boston Acoustics sub, but I prefer the bass through just the 82's alone; they sound much tighter.
The 40's doing surround sound are mounted close to the wall, so they have the foam port plug in. They're pretty good, but have nothing like the impact and dynamism of the floor-standing 82's.
I have another pair of Audience 40's that I'm in the process of biamping (DIY).
Initial results on one speaker sound encouraging; will have to biamp the other to know for sure.
I only wish my car had a Dynaudio package, instead of Bose! :P