Being new to textpattern, I was delighted to see how easy it was to update from g1.19 to 1.0rc1. Deanload the bundle, unpack it, move the old .../textpattern to the side, replacing it with the deanload, and copy in my prior config.php file.
That's it! I keep a mirror of the site on my laptop, and both upgrades were that simple.
The new system has some sweet features such as separating the edit articles page from the articles themselves, making it easier to manage existing articles. Also can specify how many articles show on a page .. nice for modem users I suspect.