I installed Typo3 last night and unfortunately it took me about an hour to realize that the Typo3 EMCAscript interface is not compatible with Firefox 3. :-(
I kept on thinking it was a rewrite rule, but in the end I gave Iceweasel a go and it worked. At that point it was 1AM so I decided to hold off on further exploration.
My initial reaction was somewhat positive - the interface is pretty complicated, but it appears to be straightforward, and looks to be very competent as a content management system.
¥