Yeah I've been using Kubuntu 7.10 on my laptop for several months now and I love it. The array of features is amazing. There is FTP and SFTP browsing available right in the Konqueror browser, and it's drag-and-drop just like Dolphin (similar to Nautilus in Gnome or Windows Explorer on Windows), even between Konqueror and Dolphin. You can seemlessly SSH into other PCs right from the terminal without the need to install or open a separate program like PuTTY on Windows. Both of these features are very useful to me because I operate a Linux virtual server, Linux web server, and Linux file server, none of which have a GUI available (I don't even have a monitor, keyboard, or mouse hooked up to the PC).
Kubuntu uses KDE vs. Ubuntu which uses Gnome. I have more experience using Gnome in the past with older versions of Ubuntu and Fedora Core. KDE is much more "Windows-like" than Gnome. This is in the sense that Ctrl-C copies, Ctrl-V pastes and things like that. I prefer KDE now, but not for those reasons. I actually prefer some aspects of Gnome that are less Windows-like such as highlighting something automatically copies it to the clipboard. Rather I prefer KDE because it is just a lot more customizable. I also find myself liking the K-apps more than the G-apps.
You can do almost anything. Anything you don't have by default is easily attainable, and it's pretty much entirely at no financial cost to the user. I'm also definitely coming around to preferring the *nix idea on what a file system structure should be rather than Microsoft's drive-based methodology.
There are a few problems though. Something frequently happens to the mouse cursor where I can't click on anything. Usually rapidly right- and left-clicking repeatedly fixes it, but sometimes I have to switch to another terminal and back to get it to work again. This only seems to happen when using the touchpad though. If I use a USB mouse it doesn't happen. Also, even though I installed the restricted codecs pack (MP3, MP4, MPG, Flash, etc.), several videos like those on NFL.com do not play.
Still though, I find myself using this laptop far more than my Vista desktop.