I have a pair; I think they sound quite good, but what you'll think may depend on what you're accustomed to. I picked mine up for free about a year ago, but my recollection is that when I looked into it that they would probably go for somewhere around $100-150.
I listened to them for a few weeks when I first got them and thought they were very nice, but I eventually went back to my Vandersteens 2ces (which do sound better, but I would certainly expect them to, and they're a lot bigger and more expensive.)
The B&W DM4s are purportedly very similar to the Spendor BC1, which appears to have the same tweeter and supertweeter, but a different woofer. Of course, I've never heard a pair of those -- I'm getting that from what I've read. If you do a search for them on here, you'll find much more about the B&Ws.