My biggest beefs are: the fact that the build system is a complete black box that fails without a good indicator of what it takes to fix it, and inconsistencies

My biggest beefs are: the fact that the build system is a complete black box that fails without a good indicator of what it takes to fix it, and inconsistencies in how events are handled, 'swipe' and 'scroll' being prime examples of events that either don't work as expected, or work in unexpected ways.