Ok. Just had them Side by Side
Impressions are that the 11.3 sounds clearer, the midrange sounds less muffled, the bass for me is definitely tighter and louder, and I believe it is slightly louder too.
I will assume they have changed the DSP so effectively this varies room-to-room and even position-to-position, but it could be the DSP has been tweaked and say for example it was peaking at certain frequencies, the DSP has flattened it more to give a more natural and true sound, hence the reduction in bass for some people.