I have been quite busy lately and most of my work has involved fixing the UI for a little project I started a couple of years ago. I havent noticed that the UI was a mess, it worked for a resolution, but not for others. Took me some research and testing to make a bit (just a bit) less messy. The new UI, not so new now, was introduced in Unity 4.6. It was an attempt to replace IMGUI with a decent system, but the result was something counter-intuitive and not so good in perfomance terms. Yes, was better, but if you go from scratching you back with a cactus to scratch it with rough sandpaper, that can be considered good too. Lucky us, there will be a new solution, coming with Unity 2919.3, though it wont be official until 2020.1. Check this nice video and you will see all the great features it offers.