Rotel RB 1070 bridged/ RB 1090

Bridged amplifiers are more suited to low sensitivity/high impedance speakers. If your speakers are low impedance your better off not bridging the amplifier. In a bridge configuration both amps see half the impedance of your speakers. In other words 8 ohm speakers become a 4 ohm load in a bridge configuration. Some speakers dip to low impedance at certain freq and at high volume this can stress amps with high current demands.

I use to own a RB1090 power amp and recommend it highly. The 380w/ch was more than enough power to drive my current hungry B&W 804 speakers.

Neither. If you can afford the 1090, you can afford a better power amp than the Rotel. Don't get me wrong, they build decent stuff, but having had a 1080 in my system temporarily while waiting for my Bryston amp to come in almost a year ago now, the Rotel had this grainy sound that was just...unnatural. I'd definitely look at (and maybe audition if you're buying new) other products in that price range.

My speakers are B&W 704. If I traded out of Rotel, which amp would you recommend in the $1500-2000 range?

I went from a Rotel 135WPC amp to a Classe CA-200 (one of the newer ones, same guts as the CA-201) and was thrilled at the upgrade. Cost was about $1500 used. List about $3000. These puppies are heavy, though, I'm amazed mine didn't get damaged in shipping!