Why are my B&W 803D speaks feel bright

The B&W are very good. The other stuff you have is not up to thier level.
Mainly the Rotel is not cutting it. (I do not know your DVD player at all)
I would say the speakers are not the problem, they are just letting you hear the problem somewhere else in your setup.
I would not worry about the amp, but the DVD? or the pre..
Borrow a tube preamp and see what it sounds like with your speakers(if you can)

Because they are. Try toeing them in a lot.

Have you tried room treatments? I'd also recommend getting rid of the Audioquest cables, replace them with Acoustic Zen.