OP, I have auditioned the D30 and D48 extensively during my search for loudspeakers that started 2 years ago and ended a few months back. I ultimately went for the, D48R because my room could accommodate it without issues.
The D30 is a very engaging loudspeaker and goes pretty deep for it's size. The vocals on these speakers are to die for - at least that is what my listening notes say, when the D30 was being played through a Naim system. But I have never listened to the 140MKII, so I am not in a position to compare.
I agree that you room is small for the D48. I completely agree with @jperry that the ribbon in ProAc series are something special. They just sound very natural.
The D30 is a very engaging loudspeaker and goes pretty deep for it's size. The vocals on these speakers are to die for - at least that is what my listening notes say, when the D30 was being played through a Naim system. But I have never listened to the 140MKII, so I am not in a position to compare.
I agree that you room is small for the D48. I completely agree with @jperry that the ribbon in ProAc series are something special. They just sound very natural.