I am currently running Ubuntu 7.04 on two computers at home. In the past, I have always found it hard to resist the urge to install the development version of the next release of the distribution I am running. This started when I was using Debian. With its slow release cycle, Debian stable did start to feel a bit tired as a desktop system.
I would find that the latest version of some software with the features that I was interested in was not available. Rather than muck about with back-ports etc., I just went and installed testing, and then unstable. These are only my own machines, and the need for stability was not critical. The only time this did bother me was when I wanted to print. I found that my printer needed to be re-configured at regular intervals. A couple of times this did bite me as I wanted to print something quick, and due to changes in CUPS or whatever, my printer was off-line.
I then moved to Ubuntu. With its shorter release cycle, I decided that I would have the best of both worlds. I could have the more recent versions of software, and not have unpredictable breakage. Two upgrades a year should be ample. Well I could not wait for the final release of version 7.04 so I installed that a few months early, to try out compiz IIRC.
Now I am trying hard to resist the urge to upgrade to 7.10 before it is released. I fully expect that it is already stable enough for my use, but it would be good to wait until it has been released to try it. Not long to go now!