I've never been connoisseur of these things, but since I'm not truly computer-literate I make a good litmus test person. If I find it easy & intuitive, if I don't stumble & get confused in making something happen or finding the cog in the machine I need to work on, it's a winner. So far, it looks like a success by those measures.
I'm not crazy about all the orange color on the dashboard page though :P. I do think I like how it's set up.
More thoughts to come as Rome gets built, I'm sure.