But I really don't get what people don't like about Oblivion's ui. It was smooth and it was organized, much more than I could say for Morrowind's "Oh look now I have to sift through the giant grid of countless items for the one I need" inventory.
It was a usability nightmare for a mouse. Two layers of tabs to sift through to get what you want, a font that didn't allow more than 6 things to be in view at a time, very few hotkeys, a very time-consuming and clunky barter menu (I want to sell this, yes, I want to sell that, yes, I want to sell another of that, yes, I want to sell this other thing, I want to sell all of them, yes, click over to see what you got, I want to buy that, I want to buy one, yes. etc... vs, I want to sell this, both of that, all of this other thing, I want to buy one of that, yes). In Morrowind, I particularly liked being able to hold down shift when clicking an item to auto-select them all, or ctrl when clicking to auto-select only one... in Oblivion, you had to go through the slider menu to select the amount no matter what. You couldn't set specific keys to go to specific menus (eg, press M to go directly to the map, or J to go directly to the journal).
I didn't find Morrowind's layout particularly nice either, though. All four windows trying to fit on the screen at once, tiny icons for inventory items, a mess of text for your list of spells and magic items. But at least the windows were movable and resizeable.