I upgraded from 9.04 on an Asus 1000HE.
No issues with the upgrade process.
2D Intel graphics performance has improved.
Wifi connect times, initial and resume from suspend, have improved.
However, I cannot use the Fn+F2 key to shut the Wifi radio off as this will result in a kernel panic. This is a known issue that hopefully will be fixed soon.
Like any new major version, I wouldn't upgrade on a "mission critical" machine for a few months.
