The huge Silver Ball of Doom the old boot animation had is now merely a tiny prop for the Flirty Floating Green Ribbon to hide behind. T_T
My Avatar Awards have a little exclamation mark where they used to be in the Avatar Editor, and can't be selected, but as long as I don't change my avatar they seem to keep showing up.
The KXE UI is much whiter than I'm used to, but other than that isn't that bad. It's not too white, just white as a major theme. Flatter, as well; one'd think the theme for the Xbox *360* would be roundness (BLADES, anyone?), but I suppose for Kinect flat is the new round.
ESPN3 makes for a nice addition, but with my college's internet connection of fail, I can't stream worth anything. Still, that's hardly Msft's fault, except there's no documented way to forcibly back off to SD quality when HD isn't working right.
There seem to be some website issues, especially if you have an XNA Creators Club or AppHub subscription, but those appear to be being resolved, and they have no effect on anything on the console.
One thing I haven't tried is pulling all storage devices. When upgrading from Blades to NXE, some sort of storage device was required, or else the update wouldn't apply cleanly, but once the update was complete you could pull all storage any things would work just fine. I read online that KXE will give an error message if it boots on a console without a storage device, but that might only apply to the 360 S, and not the 360 Original.
One final note: Convection is out. The Microsoft-wide 2010/2011 logotype is in. That is all.