Unfortunately, you bought Monitor Audios. Did you get a good demo of them before purchasing? From prior experience with the RS6, the Monitors are a bit forward in the upper mid-range/low treble which can be fatiguing to certain listeners (like me) after a while. Yes, you can try using EQ (like Audyssey Pro) to specifically tame certain frequency ranges, but this will bring about it own tradeoffs (like decreased imaging/soundstage depth/etc).
My advice would be to stick with the Marantz and Rotel source gear and go find yourself some new speakers. If you are looking for a richer sound (without compromising much on accuracy), try brands like Sonus faber, Vienna Acoustics, Dynaudio, Legacy Audio. You might want to look at brands such as Aeriel or even the higher end (Reference and Signature) lines from Paradigm as well though they are more of a "neutral" sound as opposed to warm.
Best advice is to go to the audio shops and listen, preferably on similar source components. Learn what you like. It's fun.