I've been playing with Karmic beta main on my laptop, and Karmic Netbook Remix beta on my Acer Aspire One. They were very unstable when I first installed, with instant messenger clients (both Empathy and Pidgin) crashing, and odd hangs at bootup. Then I had one major crash on the UNR that necessitated a complete reinstallation, as it wasn't recoverable, wouldn't boot into any kernel
However, another update, including kernel 2.6.30-13 and things have smoothed out considerably. Aaaaaand the intel graphics on the AAO's UNR have smoothed out rather a lot, although my AAO doesn't have the 985 chipset that's the worst victim. Wifi has been more consistant and has shown better detection.
I'm not impressed by Empathy. I've found it lacks many of Pidgin's features, such as, oh I dunno, popping up a window when someone IMs me, as opposed to just blinking their icon on the buddy list. If it weren't for the Gnome notifications, I'd never have realised that I'd been IM'd. Empathy also doesn't support mail notifications; Pidgin offers mail notifications for AIM, Yahoo, Gmail, MSN, etc. I've read that Empathy supports cam for MSN but I couldn't get that to work, nor does it work for Yahoo's camming. What it does work for is XMPP camming, buuuuuut so do the newest releases of Pidgin. I gave Empathy a decent workout but eventually went back to Pidgin as my default messenger, it's simply more mature.
Still, camming on the AAO does work on UNR now, as does the Wifi light, microphone and sound. Boot-up, though not 10 seconds on my SSD (I have an AAO 110L), is a satisfactory (to me) 25 seconds. Well, it's a CONSIDERABLE improvement over previous attempts to get UNR to run on the AAO 110L. And installation takes up 2.3 GB of the 8 GB SSD. Performance is surprisingly quick, considering it uses the Gnome environment, and resource usage is much improved; previous attempts to put UNR on the 110L were painfully slow and sucked up memory and CPU like a sponge. Battery management still sucks though, 2h20m out of a 3h battery. As a friend is considering UNR for her AAO 150XP, I'm giving it a much more thorough test-drive, hence all the details.
I did try installing the main Karmic (sans UNR tweaks) onto the AAO and was pleased to see that it displayed the AAO's 1048 x 600 resolution correctly. That bodes well for Mint users, as inability to display is one of the reasons why Mint is not on my AAO (it typically shows 1048 x 760, i think it is, and thus buries buttons, making it extremely difficult to use)
The main Karmic beta on my laptop (a 5 year old Dell Latitude with 512 mb of RAM) is unremarkable. Sound works, boot-up is fine, video works, wifi works, memory management is good. Stability is improved after the last set of updates, messengers no longer crashing. There's nothing particularly impressive about it, but I'm not throwing the machine across the room, either