I am indecisive about choice due to room size

"Sit 2’ from your speakers and listen to them. The difference between that and your chair is room acoustics."

The difference is the speaker’s off-axis response plus the room’s acoustics. 

Duke

It is always interesting when someone says they love their speakers and want to upgrade..please don't tell me you are looking for more bass. Everyone is looking for more bass. I would guess you are looking for a rich textured mid-range with good front to back layering and you would like the speakers to disappear so you are left with just the music. 

The Charney Audio Maestro would be a perfect fit for your room. Charney designed the Maestro specifically for smaller rooms. I happened to be at Charney yesterday we listened to the Maestro with Lii Fast8 drivers ($2800.00) in his 14x19x9 room. Although the room is too large the Maestro put on a great performance. Very open soundstage, pinpoint imaging, with adequate clean bass. The Maestro maintains all the goodness of the upper tier Charney offerings just designed for a smaller room friendly platform.

The Lii Fast8 is a new driver for Charney and the site hasn’t been updated yet.

http://charneyaudio.com/the-maestro.html

Duke, millercarbon, and erik have some valid points. Square rooms are bad particularly for bass, directional speakers are the best way of avoiding room interaction and a large percentage of the way a system sounds is due to the room. 
So how do we integrate all these factors. Will going to VIII's solve anything? Not really. With more bass it might even make the situation worse. This is a room for small Maggies, ESLs and some absorption on the front wall behind the speakers. Horns would also work like Klipsch Heresys or Cornwalls.  Down the line you could add four small subs like Duke's system. I really like Sonus Faber but dynamic speakers like that need more room to breath. Right now you are being assaulted by early reflections from all sides. 

Jchiappinelli77

Square rooms should be avoided. You will have a hard time overcoming the limitations and acoustic issues of a square room by upgrading any of your components. If the spare room is your only option, I would seek help fro GIK before doing anything.

J.Chip

Mijostyn

Duke, millercarbon, and erik have some valid points. Square rooms are bad particularly for bass, directional speakers are the best way of avoiding room interaction and a large percentage of the way a system sounds is due to the room.
So how do we integrate all these factors. Will going to VIII's solve anything? Not really. With more bass it might even make the situation worse. This is a room for small Maggies, ESLs and some absorption on the front wall behind the speakers. Horns would also work like Klipsch Heresys or Cornwalls. Down the line you could add four small subs like Duke's system. I really like Sonus Faber but dynamic speakers like that need more room to breath. Right now you are being assaulted by early reflections from all sides.

millercarbon

You can toss all the above bad advice. Some of it is outright plain wrong. Adding bass for example is exactly what you need. Your biggest problem is not size but being square, 12x12. But 192.168.0.1 routerlogin 192.168.10.1  would be bigger but at least as bad. Simplistic thinking combines with poor understanding. People hear the obvious boomy bass in a room like yours and assume too much bass so solve it with small speakers. Wrong.

I wouldn't go with any of the stuff you like but I wouldn't hesitate a moment to get better speakers simply because they're "too big for the room".  

Regardless of speaker you're going to want to control the lumpy bass identical dimensions causes, and early reflections. In that order.  

Lumpy bass is best solved with more bass, not less. Using multiple subs will allow you to put them in different locations to excite different room modes and ultimately achieve much smoother bass. Duke himself, owner and speaker designer at Audiokinesis, says the benefits of multiple subs are even greater in small rooms than large.

Just one of the ways people misunderstand the realities of the situation you're asking about.

Will the speakers fit in the room? Will you be able to place them with drivers at least 3 feet from walls and ceiling? Then they are not too big.

Hi all,
Thank you very much to everyone who posted. I had an idea of what issues I should pay attention to. I will write the results here again.
Best regards.