Modern Alfas are about as reliable as german cars these days, so reliability issues are more myth than fact. That being said, German cars aren't as reliable as Japanese cars.

The real problem isn't reliability but shitty dealer networks. Alfa have a knack for finding dealership networks that think it's great fun to have them in the showroom to pull people in, but aren't terribly interested in selling them or doing a good job servicing them.

My tip is to never use the dealership for servicing your vehicles (of any brand). Find a garage that has competent people, and who have respect for the work, and then pick whatever cars they are competent to work on. You don't want to spend a lot of money on a car only to have a bunch of underpaid teenagers who can only follow a manual work on your car.