I'm very pleased with it overall. Battery life seems really good even though I've selected the option to only charge to 80% to prolong battery life. It looks good and feels solid.
I didn't bother with UNR, I just set the top and bottom panels to autohide, and use Vimperator to browse which is very economical with vertical space. At first I used full screen to eke out that last few pixels, but it's generally not worth the bother. I might give UNR another go with Meerkat.
I'm trying to think of bad points. You need to hold down two keys to change the volume (fn-arrow), the screen brightness doesn't auto-adjust to ambient light. The touchpad doesn't have multitouch, but you can fake two finger click and scroll, rather than use side-scroll. I used to hit the backslash button when trying to use the right shift-key, but I got used to it soon enough.
You might want to check out this forum, for Linux on Samsung, that's were I got some extra drivers for the function keys etc.