Linn Unik as rear speakers recommendable?

I am considering to purchase these wall mountable speakers to be used as rear surround channels in a HT setup. What I like about them is their shallowness and unobtrusiveness. I wonder whether people have experience with the Linn Uniks.

In particular, I would be interested in comments relating to:
- sound quality; as they cannot be bi-amped their (limited) freq. response is fixed once and for all.
- bass range response insufficient? or is this accaptable in case one has full range front speakers?

These speakers are not marketed in the high end segment, but my impression is that if you combine them with high quality front speakers, the results could still be very good. Am I right here?

Thanks.