Last night, I upgraded my iPhone to 1.1.3 using the official 1.1.3 installer.app based hack. It would have gone smoothly except that I first answered no about whether or not to use hactivation. I should have answered yes.
So, I had to first downgrade to 1.1.1 which was a pain to figure out how to do because I could not get the phone into a restore state. Hold down power button and home button on startup. as soon as you see apple logo, let go of power button. Once I re-hacked up to 1.1.2, I did the 1.1.3 hack again, answered yes to both questions and now I'm running 1.1.3.
Everything seems stable except for a few problems like installing older themes. I had to log into the phone and symlink /var/root/Library/SummerBoard to /var/mobile/Library/SummberBoard. There is also an issue with zsh and the delete key when logged into the phone. The quick solution is to just use bash. There is some talk about a .profile fix, but it did not work for me. Customize also seems to no longer have control over the Dock so I'm back to 4 icons there instead of 5. Oh well, I really appreciate the ability to re-order applications now. I also had to install the Locate Me application and use it once before the Google Maps location feature would work.
One great security feature about this new version of 1.1.3 is that the 'desktop' no longer runs as root. It now runs as the 'mobile' user. I can't believe apple didn't do that from the start. Basic unix sysadmin instructions are that you shouldn't run apps as root unless you need to bind to a low port number... and that app should start as root and then switch to a different user once the port is bound.