To put this review in context, my previous workstation was running Fedora Core 5, with Gnome, and I've been using Fedora since it was called RedHat 6. I prefer to get work done instead of reading man pages and configuration files; I know how to edit httpd.conf or /etc/hosts in vi, but I just don't enjoy it.
My new machine had modern hardware (Intel ICH5 chipset) that Fedora Core 7 choked on, and basically the just-released Ubuntu ended up being chosen as it was the first user-friendly distro I tried that would install. (CentOS also failed, as did the Fedora 8 pre-release; I didn't get to Suse as some web searching hinted it would fail.)
The quick summary: No regrets. Ubuntu is good. Better than Fedora. Better overall than Microsoft Windows. (Far better than OS/X, but Macs and I have never really got on - we just don't seem to understand each other.)
Install starts with a live CD boot, where you can play with the system. Then install. The install went smoothly. There were very few questions, which is a criticism - I had to spend a lot of time after the install completed realizing things were not installed and having to install them. On the other hand Synaptic Package Manager is easy to use, and I can generally have the software I need installed and running within 60 seconds. I had been very reluctant to switch from a familiar RPM distro like Fedora to a deb distro, but in fact I have not had to be aware of the differences so far.
Support, via Google, is excellent. "Ubuntu xxx" has almost always given me a helpful page telling me how to setup or troubleshoot xxx.
Lots of things Just Work. Printer just worked when I plugged it in. The samba network drive was found first time. Setting up an encrypted partition was easy, as was setting up special encrypted directories, again following Ubuntu-specific tutorials. Burning DVDs just worked. My USB thumb drive just worked. My scanner too. Sound too. Gigabit ethernet too.
Getting scim-anthy working required a bit of effort. See http://tlug.jp/ML/0710/msg00295.html and http://tlug.jp/ML/0710/msg00305.html. But it was roughly the same steps I had to go through on Fedora: I need to simultaneously use Japanese, Chinese, Arabic, etc. in an English environment, which is not a common need, so I can accept a little work. I am not even sure it can be done at all on Windows?
Webcam just worked. Google on "ubuntu webcam" took me to a page suggesting I use Camorama. I went to the package manager and that was installed within a minute. And it just worked first time. It took longer to find my scissors to get it out of the packaging that it did to plug it in, install the software I needed and get as far as taking a snapshot and emailing it to my Mum.
Two problems stand out. First multimedia (Fedora was terrible here too). I had to follow a tutorial to get most audio and movie formats to play. I then had to hunt and follow another one (the one that talks about mediaubuntu.org) before DVDs would play. There are two formats I still cannot get to work: VCD (and Google tells me no-one else is having much luck there) and Real Media. The latter is irritating as, despite there being video formats that are superior in all respects, some web sites still insist on only publishing in that format (e.g. the BBC, and MIT open lectures). I ended up having to install RealPlayer on Windows to be able to watch some things. (Real Media's own Real Player For Linux installed without complaint but crashes with a segmentation fault every time I run it.)
Second problem was the 19" 1440x900 wide-screen monitor. I installed using a spare 15" monitor, no problems, then when I was ready to switch to it to be my main system I plugged in this monitor. Seven hours later I finally cracked it: in the x11 conf file it has to be referred to as Monitor-VGA-1, the "-1" on the end being critical. Without that the configuration I thought I was adding was being ignored and then it was falling back on its clever auto-detecting, and (as it had no knowledge of this particular monitor model) it was choosing 800x600 or something.
One more thing. After installing I suggest you go to this obscure place: Systems|Preferences|Sessions, where you can disable a number of services you don't need. I disabled Evolution alarm notifier (I'd stripped out the default-installed Evolution, as I prefer to use Thunderbird), bluetooth manager, tracker and visual (a mysterious one but nothing has broken since I did that). Tracker is the key one you must disable - it will continuously index your entire home partition for some search program that as far as I can tell I have never used or needed. And according to some web searching it is unreliable and will sometimes use 100% CPU.
Other other minor comments. bash has intelligent tab completion, just like zsh, but while still being bash apparently. Nice. Firefox 2.0, and especially Thunderbird 2.0, run more slowly than the 1.5 versions I was using under Fedora Core 5, without a single useful feature to compensate that I've been able to notice so far. Gnome file manager was also a bit sluggish, but killing "Tracker" (see above) seems to have helped there. Having changed three things at the same time (hardware, distro, version) I am unable to say if the slower performance is due to the way ubuntu builds them compared to Fedora, or due to bloat caused by bigger version numbers, or due to my new, faster hardware.
Overall, Ubuntu 7.10 is good, and is now my first choice of OS to install on a new machine.