During the last winter I decided to upgrade it to have two O2 sensors, one for each cylinder.
Both cylinders originally received same map and also compared to last year I also changed air/fuel mixture a bit.
On the way to Turkey we were two bikes, mine is 2009 and other one was 2007 GSA with slip-on installed with KAT removed (I have also Akrapovic 2-1-2 full racing exhaust + K&N air filter). When comparing fuel consumption there was very little difference, depending on the road some ½-1 liters for each 500 km so nothing.
Now after driving some 20tkm with these two O2 sensors installed I have now these maps:
So yes, there are some difference on cylinders, not much but there is.
Compared to last year, bike runs even smoother than before, especially when going slow on though roads.