I really hope I didn't offend you. Honestly, I didn't see that one coming. If you read some of the other responses, these types of questions are asked very frequently; just under very different circumstances.
I have to agree with J135. There is nothing wrong with the Adcom but the Rotel is in just another league. Also, if you are just going to be using it in a 2 channel system, you can do a vertical biamp if your speakers allow. All you need is 2 sets of binding posts on the back of your speakers. Just run speaker cables from each channel of your Rotel to a set of binding posts on the speakers. That will allow you to take advantage of 4 of the 5 channels on the Rotel instead of just 2. This won't just give the speakers more power, they will sound better, as well. Just make sure that the 2 channels you use for the left channel gets the left signal from the preamp and do the same for the right.