Hi Tim

I "upgraded" from a 561 to a 568.1 and was actually disappointed that there was such a modest discernible difference between the two in my system at the time. A subsequent change to the 568.2 was a marked improvement, the rest of the system was the same IIRC (5 DSPs and analogue sub). This was with the original firmware.

At that time, I was listening to music in 2.1 mode, with the music/movies balance as 80%/20%.

I'd recommend you skip the 568.1 and go directly for a 568.2 (and the MM version at that, to keep some options open for yourself in future). It was, and still is to this day, a superbly musical piece of kit. The 2.5b firmware was a nice SQ enhancement from an already high base.

Cheers

George