Sorry for my slow reply. I'm going to do a video this week for our YouTube channel on engine choices for an A3. I went for the 1.4TFSi which gives economy and decent power.
TDI with the DPF are a problem if you are a low mileage driver and diesel prices have been creeping up of late.
The TDi will remap nicely though and seem to give superb economy no matter how hard they are driven and enjoyed.