Possible minor spoilers
I too managed to get on SE today, twice in fact. Overall I think they've done a very nice job indeed - I can't remember the last time it look so good (it probably never did). A number of animatronics have been upgraded and are now more "Jack Sparrow" than "Carousel of Progress" (I still love CoP).
It's clearly a work in progress as there are random tools visible in the dark (only if you look where you probably shouldn't). In the tunnel just before the "on this our spaceship earth" I saw a trolley jack which was funny. The cars did stop at one point for about 4 minutes and I confess I was rather hoping for an evacuation...
As far as the audio goes I think I prefer Jeremy Irons version. Of course it's very early days but Judi Dench sounds a little like my grandmother trying to make something sound more interesting than it really is.
The only disappointment was the current ending but I imagine that's not yet ready to be seen properly. How whatever they add will mesh in with what they have there now (on the screens) I don't really know. I think it could be a sort of sensory overload. But the effect they've put in as you start to drop back down is mesmerising. I'll would ride it just for that.
It's really great to see that instead of ripping it all out and putting in a fast thrill ride, they've cherished what they had, given it a polish and made it better.
10/10 to the Imagineers.