I run B&W 685s off of a 15 year old Yami receiver and I have been very happy. I am kind of a bass head and most of the music I listen to benefits from good deep bass, so I bought a HSU VTF-1 to match with the 685s. All total, its a $1200 investment and I couldn't be happier. This is my first foray into hi-fi, so I have no frame of reference besides the Paradigms my roommate had in college (running off of a Luxman amp), so you could say I was spoiled very early. But to my ears the rig sounds very good.
There are other issues that affect imaging besides the kind of speaker, IMO. I was having some of the same imaging troubles you describe with my 685s, until I completely re-arranged the room to run the stereo and speakers on another wall. Now the sound is much better. I have the sub in a different corner, bracketed by concrete foundation walls, and the improvement is easily heard. I also place the B&Ws 3 feet from any wall, and I suspend the speaker cables by heavy thread from hooks on the wall to avoid any vibration.
There are other issues that affect imaging besides the kind of speaker, IMO. I was having some of the same imaging troubles you describe with my 685s, until I completely re-arranged the room to run the stereo and speakers on another wall. Now the sound is much better. I have the sub in a different corner, bracketed by concrete foundation walls, and the improvement is easily heard. I also place the B&Ws 3 feet from any wall, and I suspend the speaker cables by heavy thread from hooks on the wall to avoid any vibration.