There's been some negative press about Karmic, saying it is really buggy and incomplete. Others haven't had too many problems, and say that the negative press is unfair.
One small note: there are bugs with every new operating system release that I have used. Ever since I installed Windows 95, I have seen issues with new operating systems. They don't always work the same as before, they change things, or introduce new bugs, etc. This is normal. Surprisingly enough, I have been impressed with past Ubuntu releases (Feisty and Jaunty come to mind) where things actually upgraded really smoothly - in fact the move from Edgy to Feisty is what really sold me on Ubuntu, it was a really great upgrade. Before that I was still using XP as a primary with Edgy for messing around.
My issues with Karmic haven't been terrible. My network still works, so does my sound. The issues are more with papercut-like things. There are little things that come up that are not giant failures (I remember back in Gutsy when you wanted to install the Nvidia drivers you had to kill the X server - see my post about it) but are annoying little things that you kinda go, "well that's annoying." A small list of them:
- Flash doesn't recognize mouse clicks - annoying for watching non-autoplay Youtube embeds, or using Google Analytics. A fix can be found here.
- Suspend/resume and compiz - sometimes when I come back from suspend compiz crashes. Slightly annoying since I'm using Avant Window Navigator which depends on compiz's livelihood. It's not a big deal, it's just annoying to have to go to Preferences->Appearance and start compiz again.
- Empathy - I posted about this here already so I won't go into details again, I just find that Empathy doesn't really offer anything over Pidgin. This is not a papercut, more just a "why did they do that?"
- System Tray Icons - sometimes system tray icons look really weird, and there's a bunch that don't make sense. I have one that says my network cable is unplugged, even though it is quite obvious that it's not since I am on the Internet as we speak. Also some of the icons are messed up, they show a solid grey square behind them instead of the gradient image I have for my GNOME panels. Again this one isn't a huge issue, just ugly.
- Bluetooth Applet - my fix no longer works since they changed the Bluetooth applet. It's nice that they show a system tray icon for Bluetooth, unfortunately there's a bit of confusion. When I right-click, it says "Bluetooth: On" and has a menu item to disable Bluetooth, but when I go into the Preferences panel it says Bluetooth is disabled and has a giant button to turn it on that doesn't actually work for me, when I click it the button goes grey and nothing else happens. Unfortunately the dialog has nothing else than that except an option to stop displaying the system tray icon. So I'm not really sure what to do here, if I fix it at some point then I will blog about it.
- Wine is weird to install. See my fix to install it.
What has gone right with Karmic? Well, not a whole lot I think. It isn't horribly broken, which is nice. Ubuntu One is really useful, and I think the Ubuntu Software Centre is a lot cleaner than the Add/Remove programs that used to be there. Also it upgrades to Firefox 3.5, which is a bit speedier than Firefox 3.0.
All-in-all, I wouldn't say Karmic is a bad release, I just don't really see much point in using it. If you really want Ubuntu One then it is good, but other than that if Jaunty is working for you then you should probably just stick with that.