The only transmissons available for the MkV GTI is DSG or Manual. I have driven both but after driving the DSG I found it hard to not want it over the manual. I have two reasons:
1 - I still commute in Atlanta traffic
2 - I auto-x and you are not shifting ver often even with a manual. I can actually shift more with the DSG
The only issue that I have seen so far is if you are a big modder, there is still an open question on big turbo kits or really big horsepower and if the trasmisson can take it. Since I am not looking for big horse power it works for me plus, you can upgrade the ECU and do about 90% of all other mods.