I've got the same model and the obvious advantage is fuel economy.
I've done approx 4000 miles from new, and I notice the car going into 2 cylinder mode when cruising along steadily. I have to say that the only way I actually notice it is through the dash showing the symbol, not because of anything discernible with the engine.
When running in 2 cylinder mode if I cycle to the instantaneous mpg, there is a big step up in efficiency.
Prior to purchasing the car I checked to see if there had been any history of problems with the engine in the golf, Audi A3, q3 and Leon's, but nothing appears to have been reported with regards to issues. The old 1.4 twin charged engines did have issues, but that's a different engine with different pistons and bores etc. So fingers crossed this engine and the 2 cylinder on demand functionality stays as good as it has been so far.