Well iv'e purchased the Yamaha RXV767 ( £349.95 ) over the Yamaha RXV667 ( £299.95 ) & the Pioneer VSX920 ( £299.95 ) as to my ears it sounded better than either of the others, so well worth the extra £50 IMO.
A clearer, cleaner audio emminates from the speakers when the Yamaha is plugged in over the Pioneer. In fact i found my Denon 1910 sounded very similar to the Pioneer 920 both have bass a plenty, so does the Yamaha when needed, but the Yamaha seems more controlled within the sound field & more natural sounding.
My Denon 1910 ( now to go on a well known auction site ) seemed to give the centre speaker in my system far too much bass, it didn't when i previously ran a Kef c95 centre & Musical Technology Harrier speakers through it. Ok i know i could probably do with a Dali Ikon Vokal 2, but the Yamaha certainly has made my centre speaker sound like a different speaker & brought out the best in it.
Setup of the amp was relatively simple using the supplied microphone to set the speaker distances & levels ( reasonably accurate ). Using my SPL meter to alter it i found that there was only about a 1-2db alteration to make to get the settings right.
I will just have to see what it is like in a few months time when it is all run in. So all in all i'm well pleased with my purchase having got it home & all set up.