I bought my 2013 STI last April. Tuned it with Cobb stage 1 for 4ish months then went with an e-tune from Clark Turner. I reset it back to stock in September in anticipation of an oil change and move to Colorado. 2 days before my oil change my motor blew on the stock tune at 6000 rpms shifting into 4th. I only had 5700 miles on the car.
My nearest dealer is very small and they did not ask questions, but it was Avery stressful few weeks. I've left my car stock all winter and I'm really on the fence about whether or not to retune it in the spring. I've wanted an STI ever since I got my drivers license (30 now) it's such a bummer to have zero confidence in my engine.