I have spent quite a bit of time listening to and working with the 568 and 861. I have been asked a lot about the sound comparison between the two, and I must say that I can not hear any difference. What you get with the 861 is more flexibility and a longer life span. But if you are a value oriented person like myself, you have by far the best value with the 568 and IMHO sound quality that is no different then the 861. Lots of folks talk about how limited the 568 is in video switching and that is true. But I am always looking for the best picture quality and would never use a sound processor to run my video through anyway. I always run my video signals directly to the video processing equipment and/or to the display device. So it really does not mater to me that the 568 does not have much in the way of video switching. An 861 will cost 3 times what the 568 will cost once you put the cards in it.
I strongly recommend getting your software upgraded on the 568.

Hope this helps.

Al

7.1 system 568.2 (mm installed but not used) DSP5500 L&R, DSP5500C Center, DSP33's sides and rear. Pioneer Elite PRO-620HD monitor.