Well, I'm having a little anxiety attack, but I think I'll survive.
When I found and started using Toodledo, I noticed a "for real" decrease in my stress level. No joke. It was that helpful. I attribute this to the Hotlist and the tagging features and the very very very simple UI.
My first observation is the disconnect between the view and the view's label. Before, the tabs were directly above the view and there was no denying what you were looking at. Seeing the view label on the side, and seeing it highlighted in such a faint way, is worrisome. I hope I get used to it.
The Add Task button, although it's bigger and closer to the action on the upper left doesn't look very clickable. On rollover, the text changes from one grey to another slightly different grey.
The darker color scheme grabs my attention unnecessarily. The older UI had no major dark spots anywhere and so my eye wasn't drawn anywhere arbitrary. The dark gray bands and the dark blue band on top keeps grabbing me for no good reason.
Again, I'll try to get used to it! :-)