Not sure why you went the BMW route if reliability was your reason for leaving the GTI.....but to each their own. Can't see most of your complaints as enough justification from getting rid of it but I do sympathize with any 6MT problems because the 6MT is trash.
I'm a manual to the grave guy but to anyone out there thinking about getting into this platform, I really think the DSG is the only way to go. Unless you're very mechanically handy and don't fear clutch or, worst case scenario, engine labor down the road. This is especially true if you plan to tune the car.
Even my upgraded Sachs performance DMF clutch started acting up before I traded the car in recently. Was getting worse over time and ended up sounded like a damn diesel truck, chattering like a SMF pucked unit lol that and the few loss of crankshaft sync codes were enough to scare me out of it before the crank went for the last walk. Oh....and I wasn't tuned.....and the car only had like 13K miles on it......