Got it up and running, even bumped up the res to 1024 w/ details and textures up to 5 and didn't notice anything terrible frame rate-wise. (although that would probably change when the maps actually had real, live players on it)
Running Nvidia 7600, Intel Core 2@2.1 ghz and 2 GB RAM.
Like the good Cap'n, I'm having a little trouble with the player movement and the general "heaviness" of everything. I was expecting it, but still hard to get used to.
I like the Bio rifle's tweaks (Secondary does damage over time instead of damage all at once), just 'cuz it looks neat to see the stuff hanging off your opponent for a second before they gib.

But primary still feels as useless as before, ditto link gun primary.
Haven't figured out how to toss grenades with the rocket launcher (I think that was supposed to be back in UT3), or how to do skate tricks with the hoverboard.
The new weapon bar is more useful I think, showing you only the weapons you're actually carrying.
The weapon models look awesome, especially the Redeemer! But in the end, I'll probably end up turning them off since they cover so much of the screen.
Going to try some online now...