My only question is how many people posting here have 'never' played SE:IV. All the 'UI Issues' seem to stem from comparison to SE4. Like listening to people who are extremely resistant to change. I'm not saying you are wrong to do so. I'm saying that opinions based on comparison are not 'fresh views'.
Personally I find nothing wrong with the UI in terms of functionality. (my only rub is I do not like the SE3 % type of research allocation, I much prefer the way SE4 did it with queues.)
Stats: Since the release of SE5 Aaron has made 656 fixes, changes, and additions. That my friends is allot of hard work. Rest assured Aaron will continue to make changes, additions and fixes for a good long time. He wants this to be the best it can be. (as do we all) but he is just one man. IMHO He puts other developers to shame when it comes to listening to their fans and catering to their wishes.
You can nit pick till the cows come home, or you can let the new design grow on you. SE5 is sooooo much more 'Modable' than SE4. You can tell that Aaron had 'Modding Features' as one of his top priorities. This is a Modder's game come true. It could well have been called "Space Empires Construction Set" (including the basic game engine to build upon).
Anyways, I think you people are judging by comparison and each and every one of you see what you believe is a 'better way to do it' and in seeing this become obsessed fail to see and adapt to the games current state.
Nuf said.
Cheers!