Assuming competently designed components (reasonable assumption for any gear from mainstream manufacturers), the speakers and the room acoustics are the biggest determinants of the sound quality of your room. You know your speakers are good and you are not under powering your speakers. Consequently, as others indicated above, the room is where you need to focus.
Amplifier design is a mature science. You can pay as much as you are willing for especially elegant implementations of this science. I believe there might be some miniscule difference in performance. However, if we are asking if that difference is audible, and further asking if that difference is so obvious that you could hear one setup one day then listen to the other on another day and hear a clear difference, it is safe to say that the difference you hear is not due to the amp (or pre-amp).
Again, for CD players, there may be some slight differences, but nothing like the difference you describe. My personal opinion (and I am calling it opinion - I have spent little time researching CD players) is as long as the transport is quiet and I can live with the load times, a CD player works fine.
By the way, I speak from experience. I have an Emotiva XPA-2 sitting in my basement collecting dust while my Denon AVR powers my HT. I've been holding on to it for two years, hoping to find opportunity/justification to use it somewhere. Time to give up that fantasy. Thanks for reminding me I need to get it in the classifieds!
As for the bickering, we are passionate about audio and it is pretty common for someone to speak their heart as they perceive truth. Changing amps has been the solution for many who had low powered receivers, or demanding speakers. However, this does not apply to your situation.
And, as you manage to comprehend my run-on sentences, your English is pretty damned good!
