It sounds like you are in a similar position to me, where you have combined relatively modest components to achieve results bigger than the sum of the parts.
I've been through a shedload of kit including some much more expensive stuff, but never have I matched a system so well and achieved such engaging results. For me, the desire to upgrade has gone away, because I would fear upsetting the balance and it just doesn't feel necessary. There is a point at which this whole hobby just becomes indulgent and compulsive rather than being about enjoyably reproducing the music. I've been there and I'm not going back.
I'm referring in the above to my main system (first in my signature), but I am also very satisfied with the Sony/Rotel/Q set-up and can't justify any changes to that either. I do have a second Rotel CD11 Tribute sitting in its box, but I will continue with the Sony CD player until it dies - it never hurts to have a spare player that could slot into either system. The Technics all-in-one in our bedroom is what it is, a very capable compact system well suited to the kind of listening that takes place in that room.