I put a lot of effort into my app. I spend about 50% of my time on triaging / fixing / preventing bugs. We check every crash report that is logged, and we attempt to reproduce every issue reported by customers as quickly as possible.
By now, a significant fraction of bugs are bugs in Apple's frameworks. We try to report them to Apple, but they are ignored, or simply closed because they are related to deprecated APIs.
Of course, customers don't complain that Apple frameworks are buggy -- they complain that our app crashes! So Apple has no incentive to fix it. (If the bug affects Apple apps, it has a higher chance of being fixed. If a framework isn't used a lot by Apple, it will be full of bugs)
So we have dozens of workarounds in our code, and have stopped using some frameworks altogether (if possible).
But I can confirm that Corbin was quick to review bugs -- NSTableView related bugs were the only ones were I got fast feedback.
I received an email yesterday that a bug I filed in 2013 in the Android Google maps SDK has been assigned to someone. Might as well just not fix it now.
Additionally, something will work with the stock SDK, but will break on Samsung devices (e.g. camera SDK).