The best of them can indeed create a holographic soundstage which you can actually walk into the soundstage or "view" it from any location in the room without worrying about a sweet spot (mbl's are great at this, as were the original Ohm Walsh speakers and, to some extent, my speakers, though they're not a true omnidirectional design). Channel separation is not a problem at all. Pinpoint imaging is not as pronounced as with conventional designs, though--the images are there, extremely palpable and three-dimensional, but perhaps a little more diffuse than you might be used to. On multi-miked and pop recordings this can be a bit disconcerting; on well-recorded material, particularly where there is a large soundspace recorded, it can be surprisingly realistic.
