Icon-based means giving even less information than the default Bethesda UI gives - it wouldn't even give you the name of the items prior to scrolling over them. That seems like a massive step backwards. Unless the icons actually mean something (like 'amount of space taken up by this item', for an inventory like Deus Ex or Diablo), using icons instead of text is silly.
This. Very much this. Morrowind's interface had some incredible features, some of which I miss sorely, but the icon based inventory is not one of them. Have you any idea what a pain it was finding specific items when your only reference is a 64x64 icon? I don't even want to think about the fun I had searching through my hundred identical looking potions...
Name, WEIGHT, and value are the keys, preferably displaying as many items at once as possible while retaining clarity. I adored DarN's Oblivion UI because it made intelligent use of the space available to display a lot of information clearly. I cannot express how utterly I loathe some aspects of the new UI, but I'll have a go specifically for he skill trees. They were captivating and pretty for the first 30 seconds, like every form over function solution to a problem, but frankly I'd rather have a spreadsheet than the scrolling expanses of glittering blobs we have now. The actual perk trees are a particular horror. Zooming in on any given perk has the hilarious side effect of cutting off pretty much every perk in the tree. 26" of 'Snake Blood' - that's it, can't see the prerequisites or follow ones, just one glowing blob on the entire screen.