The simple answer to this question is yes, you are expecting too much. That size room should be treated like a small studio control room. Listening in nearfield would be ideal with your seating position well forward of the back wall. Small sealed monitors are your best bet otherwise the room modes created by those big drivers or port or transmission lines will all but kill the detail put out by those expensive floorstanders.
I would be thinking Raidho XT-1 or ATC7 or 11 or small Harbeth. All of these will do justice to your other equipment.
It is definitely not something to despair over though having to move to smaller speakers. If you listen in nearfield you will get all the bass you could desire and no reflections which is why studios work that way. Sound engineers know what it's about. And by removing those reflections you will probably hear more amazing detail than you have heard in your life, regardless of speaker size or price.
Also get as much acoustic treatment as possible. Something like this below: