I'll be honest, the bottom of your previous UI was fine, I think it was just the main playing area that was perceived as a little messy. What with the cast bar's location, and the button timer thingy's location.
As for action bars, well personal preference, I can understand why people might like to show them. Personally though I'd prefer no buttons on screen - unfortunately I don't trust myself binding potions, I always end up hitting that exact key by mistake - I never hit the wrong key until I start binding pots, and then I mash them all the time, god knows why, but I don't really fancy wasting pots, so I have a couple of buttons on screen unfortunately :P