What helped STI is that they used ramped barrels a lot, and they knew how to fit them. Kimber and Springfield used ramped barrels from time to time as well, but they seemed to be fit by a variety of random blind dipshits, and their 9mm guns were usually not properly sprung.
Sponsorship and advertising aside, when you deal with competitors whose guns actually spend more time in use than in the sock drawer, you tend to identify issues and (ideally) resolve them. I've seen companies try to get into the competition world, get hit with a tsunami of complaints and feedback, and quietly slink away from it all, concluding competitors are just too much damn trouble to deal with.
The well-respected shops like EGW have built comp guns for years; they learn from their failures and incorporate those lessons into their parts. STI does the same, but their attention to detail seems to wax and wane from month to month, depending on who owns them.