Well, I'm going off on a tangent here, but I bought a pair of Swans M200s from John at Gustosounds when he listed recently on the 'gon. Figured I'd try them as cheap self powered surrounds. Yeah, I know they're not dipoles or bipoles, but I figured for the price I could try and offset them a little bit from the listening spot.
After about 60 hours of break in I can say I'm reasonably impressed that such an inexpensive speaker sounds as good as it does. Piano sounds like a piano, guitar sounds like a guitar. High end is clear and not harsh, low end (for its size) is not bad. It plays louder than I need it to without obvious distortion. There's a small range in the vocal area that sounds a little boxy, but I haven't gotten them off the floor yet. It makes pretty nice music; nice enough that if I can be satisfied with their placement as rears I think I'll like them!
I've heard that speakers have gotten better, for the money, over the years. While I've heard that being true with more costly models, I guess it's also true for low priced jobs, if the manufacturer cares to do it.