Agree with Bob - upgrade your speakers and keep your Rotel electronics. There's many speakers that outperform B&W's CM range. I'd seriously take a look at Vanns and find a pair of the Energy RC-70 brand new for just over $1k. They originally retailed for $2k/pair and sound more natural and non-fatiguing than the CM7s and CM8s I've heard. Or if you want even better (but much pricier) performance, check out Dynaudio.
Tube Preamps
I was wondering opinions on whether or not a tube preamp might fix or reduce my overly bright sounding system. I am currently sourced by a Rotel RCD_1520 with Rotel RB-1582 2x200 watt amp, Rotel RC-1580 preamp with B&W CM7 speakers. I know the speakers are a tad bright, but when I disconnect the Rotel amp/pre and reconnect my old NAD c317 integrated, it sound great. I like the warm sound and deep bass of the NAD. Isn't the amplifier just amplifying what it receives from the preamp? Is it possible for an amp to be bright?