Hard to beat any of the latest Yamaha RX-30XX models. They really do sound rather superb and when hooked up to a good pair of speakers, sound fairly amazing. My current setup is a RX-A3060 and it drives Aerial 5Bs and CC3B just fine to levels much louder I care to listen to. Prior to that I had the RX-A3040 and found it to be a fine, reliable product.
As to switching between a pair of speakers, I use an external switch (MapleTree Audio from Canada), but in reverse. I use it to switch between receiver and Cary Audio SLI-80, but for most background/daytime listening, I use the receiver and quite frankly I am very happy with it. Hard to beat Yamaha reliability and overall warmer but detailed sound.
As to switching between a pair of speakers, I use an external switch (MapleTree Audio from Canada), but in reverse. I use it to switch between receiver and Cary Audio SLI-80, but for most background/daytime listening, I use the receiver and quite frankly I am very happy with it. Hard to beat Yamaha reliability and overall warmer but detailed sound.