The dept of the room is very important:( you do speaking here of ft. instead of meters in the US). Take than the room with the largest dept -side, (speakers on the shortest wall ) otherwise you can have more resonance. (And give your “basses” come across as woolly) . Try it out : the sound will be different. And take the room that sounds best to you ! Enjoy your music !
Should I switch to a larger room?
My current listening room is 10x12. Since I live alone, I could make my master bedroom my dedicated listening room. It is 13x18. Switching rooms would be a PITA, but is it worth doing? My speakers are MMGs and they will be getting the Peter Gunn mod in the fall. I do have some room treatment from GIK Acoustics delivering in a few weeks, but what I ordered was based on my 10x12 room.