Well Tiger arrived yesterday (Thursday) and after backing up my PowerBook I set about the installation.
The upgrade proceeded without any hitches. The PowerBook is now noticably slower after re-starting but I am putting that down to Spotlight indexing the hard drive – the battery is being eaten up faster than normal as well giving me more reason to believe more disk activity is happening.
The new version of the Mail app looks well and the search works well in Mail but all previous emails had to be imported before Mail could be used and this took a considerable length of time.
Oh, don’t forget to check out the RSS Visualizer [sic] screensaver – it really is cool!
Everything else seems to have gone smoothly enough – I’ll update this post later today and say if things have sped up.