just my .02
2010 WRX, stock motor/tune
78,000+ mi and counting
all oil changes performed by the dealer every 3000-3500 mi.
30k and 60k services performed by IAG Performance with K&N air filter.
never a single problem. i do NOT baby my car either. i think if there was a problem with the tune, it probably would have happened to a lot more people. i thnk most of the failures are more probably a result of a defect in the engine, not the tune.
soon i will have a Speaco TMIC + DP + "stage 2" protune with COBB AP, though. so itll be a bit moot after that.