PJ:

Yeah, sorry...didn't mean to indicate that they operated the same.  I meant, rooms need treatments, so take the room you've got and treat it, rather than wondering about the difference between a few feet.  That's all.

 

I concur that:

 

rectangular untreated > square untreated

rectangular treated > square treated

but also, in general, no matter how your room is shaped:

treated > untreated

Amen brother, amen--I agree that you'll always get the most out of your speakers if you treat the room they're in.