The truth is that Karmic Koala has a few bug, just like any new release.
Ubuntu is a "bleeding edge" distro: latest versions introduce new features that come with bugs.
Which is why the Long Term Support version is still at 8.04 (Karmic is 9.10).
Want stability? Stick with the LTS. Want the latest features and hardware support? Give the latest version a go, but expect a few bugs. Want a good compromise? Update to new versions a few months after they come out when most of the bugs will have been knocked out.
We issue a new desktop and server release every six months. That means you'll always have the latest and greatest applications that the open source world has to offer. Ubuntu is designed with security in mind. You get free security updates for at least 18 months on the desktop and server.A new LTS version is usually released every 2 years. With the Long Term Support (LTS) version you get 3 years support on the desktop, and 5 years on the server. There is no extra fee for the LTS version, we make our very best work available to everyone on the same free terms. Upgrades to new versions of Ubuntu are and always will be free of charge.