MPG is dependent on so many things - driving style, how busy and long your commute is, what gearbox you have, what road speeds you are generally on etc.
I average 32mpg in my Golf R manual at the moment, on a 20 mile each way commute with relatively uncluttered roads. I have a heavy right foot to get to my desired speed but drive intelligently to preserve my momentum and minimise braking when i'm there. DSG is 10% thirstier in real world driving. If I was stuck in inner city traffic with DSG i'd be thinking that 25mpg was a good result.
On my commute i'd expect to get 32mpg in a DSG GTI and 36mpg in a manual one.
If mpg is of huge concern to you and you want more that 35mpg without driving like a nun, you are looking at the wrong car - a GTD with a tuning box would be the better car to have (240ps, 500Nm, 50mpg). The GTD manual clutch is very resilient, the GTI and R clutches are not.