Ubuntu 6.06 LTS five months later
After some months of use I think I can provide you my impressions on how this Ubuntu thing behaves.
I used to be a SuSE Linux user since 8.0 and then, after 10.0 I had several minor issues with some hardware. I decided to give Ubuntu a go and since then I have succesfully migrated six different systems desktops to it. I have also installed more than four other copies on several relatives computers. The net result is all of them are happily running.
I have been consistenlty using Ubuntu on a daily basis since mid-June and I'm very happy with the result. I was familiar with KDE and I am now using Gnome and I cannot complain either. It just works, though I am sure some of the days I needed to pull one or two tricks out of the many on-line forums about Ubuntu (like getting 3D acceleration on some ATI cards). If you use Ubuntu Dapper Drake I can recommend you this site.
My advice is: try it out. If you do not like you can get a refund. Till now it Ubuntu is the only distro you can get the CD shipped to your home for free.
However, if you do not have Internet access your experience might well be not half as good as mine, because Ubuntu installs from a CD that contains only a small set of applications. Most of the rest has to be pulled out of the 'net.
Update: Just when I thought it still might take a while, Ubuntu 6.10 is just realeased.