I'm a great fan of this 'little speaker' and have been fortunate to have had 2 pairs, mark 1s and then mark 2s. Their midrange is hard to beat (particulalry good for acoustic music in my experience) and have fantastic transparency, but as previously mentioned, though you can certianly hear the base you can't 'feel' it (if that makes any sense!)
I have a small room which favours the IBLs (mine are the common black variety) and though I'm lucky enough to have a pair of SBLs the IBLs just suit the room better. I use them in an all Naim active system with 2 x 250s a Snaxo and a Supercap and postion the IBls right up against the wall with no toe in - works for me!
As SW quite rightly says a pair have just sold on Ebay for £300, they were mark 1s but from the photos looked to be in fine condition. So don't dispair they do come up from sale from time to time! For what it's worth I bought from this forum and Gumtree (I know!)
Hope that helps a little. Don't give up JH they will turn up ... eventually!