I find it's all in the service history, and a well maintained old Audi will be more reliable.
Sorry to hear of issues with the a2. They're going to be a future classic for sure. There's a very strong, knowledgeable and friendly a2 club which might be worth joining (not that I'm trying to get rid of them you, I just want you to be able to get the best advice). We do t ge t many a2 owners on here to be honest.