Is the Rotel lacking in some area that you are looking to improve? The Rotel is actually a good choice with B&W speakers, in general (check out the Rotel reviews in any of the British Magazines, like What Hi-Fi) and the Arcam CD72 is a nice unit as well. Your equipment is well matched for its price/performance ratio level. My guess is that if you look to seriously upgrade your amplifier, you will wind up having to upgrade your speakers, as well.
Regards, Rich
Regards, Rich