I purchased and installed Tiger last Friday, the day of its release. I was impressed by the speed and polish that it had and all was well.
Until Monday night when I got a kernel panic on shutdown. I restarted and shut down again to get another kernel panic. I eventually reinstalled and the kernel panics went away until the next morning. Last night I did an archive and install and then manually moved filed between the old and new systems. I then restarted a heap of times and so far so good. In general I'm quite impressed with Tiger but I was glad that I was fully bakced up when all the fun and games started. Tiger uses a completely different kernel than the previous OS and so any kernel extensions from third parties that are not written for it are likely to cause problems up to an including kernel panics as I got. Things like Norton utilities and anti-virus are guaranteed to cause grief.
Anyway, in general I'm quite happy with Tiger but was pretty annoyed at the grief I copped with kernel panics. I felt like a Windows user!
All I need now is viruses and spyware. In the end it might give me an excuse to upgrade to a G5 and that couldn't be a bad thing.
Cheers,
Bruce