You guys are running a bunch of concepts together. Problems, optimization, usability, and bugs are very different. Bugs are actual problems with the code that prevent you from doing something, cause FC's, or cause inappropriate responses and affect the stability of the phone. Optimization affects the speed of the UI, battery life, and h/w and graphics performance. Usability is how well the phone performs a specific function. A problem is subjective and most likely falls in to one of the other three categories; at least for s/w.
.11 is relatively bug free. It can definitely be better optimized and we've seen signs that 2.X will do that. Usability is one of those things that not everyone will ever be happy with. Everyone hates the three dot menu but that's an exception. When it comes to how the phone performs a specific function HTC picks what they think will please the most people. Not everyone will agree with their choices in 1.X, 2.X, or JB. Personally, the usability feature that bothers me most is the capacitive buttons staying lit when they shouldn’t, like during video playback or when the phone’s in its dock.