Finally got the netbook upgraded earlier today. It took two goes over a span of about 24 hours, which I'm guessing was because my mirror hadn't fully updated when I started, but here we are:

Not much has changed on the surface. A few of the icons look a little different, but that's pretty much it. At least with the theme/icon set I'm using.
Performance seems like it wants to be faster, but is being strangled by the weaksauce hardware I have it running on (it's an Eee 900 with the Celeron M and crap SSDs). I'll have to get it running on something that sucks less to gauge that properly.
One thing that stands out, and will require further testing, is the ath5k wireless driver seems less failtastic now than it used to be. I've never been happy with this driver, it seemed like it was rushed into the kernel way before it was ready purely to replace a piece of proprietary software that, apart from being proprietary, worked far better. It's not perfect, but it seems like an improvement.
I'm really starting to get pissed off with Ubuntu moving or removing controls panels about for no good reason and often without decent replacements. Over the last few years a filesharing configuration tool, an X configuration tool (the best I had ever seen in any distro ever in 10 years of using Linux), a sound scheme tool, the system control (Shutdown, restart, etc) menu and possibly others I can't remember off-hand have been dropped or moved around out of the blue. This time, it's the Software Sources panel. It's been removed from the System Administration menu forcing you to either go through Synaptic or the Software Centre, which is annoying and unnecessary.