As someone mentioned on another thread on room acoustics “empty rooms make much….reverb”I'm going with the smaller room.
Definitely need to treat it tho. At this point my speakers sound very bright. Any sort of sound echoes and seems so hurt my ears.
I imagine this would be true for both the rooms.
Being able to pull your speakers 1/3rd into the room and having your listening position 1/3rd away from rear wall is a privilege that should IMHO not be dismissed lightly. A carpet on the floor and a couple of shelves full of books at the first reflection area on either side walls is a good start before making permanent decor and treatment choices.
If you are not pressed for time and have a relaxed deadline you could experiment more to make a more deliberate and considered choice perhaps?
You could also consider other possible reasons for “bright” sound other than the rooms themselves.