Hi, everyone, just wanted to share my Slackware experience.
I just installed Slackware 12.0 2 days ago and, surprisingly enough, everything went fine. I've been using Debian/ubuntu for three or so years, but I consider myself a "newbie". I'm not afraid of command line (in fact, I don't like using GUIs for doing what I can do just using nano and root passwd), but I wanted some challenge, so I went for Slacware.
It installs OK, everything is clear and well explained. You know what to do at every moment. I went for the "full" install, which copies about 4 GB of packages to my HD. I think this may be the key for a painless installation. It ships with LILO by default, but I chose to reinstall GRUB from my Debian etch install and modified it, don't ask me why. I feel more comfortable using GRUB.
Ok. Boot-loader is configured. Next: adduser and configure X. I did startx and it was all fine, except the mouse, the wheel was not working. It's a Logitech MX518, so I basically checked if evdev was installed. With a 4 GB install, the answer is "yes", as I expected. So I brought my mouse settings from Debian's xorg.conf and it worked!. Back/forward buttons worked on firefox, not on konqueror, so a little more tweak was necessary. Installed imwheel from linux-packages using Kpackage (it's a breeze to install packages) and using it I was able to use my side buttons.
Nvidia drivers: just download the official drivers from nvidia, sh ./NVIDIA as root, edit manually your xorg.conf and there you go. It can't get easier than that (Windows install is tougher, actually!)
I only miss my apt-get (or pacman, from Arch...a good CL package manager). I think there's one thing called slapt-get, but you've got 4 Gb of installed software, so probably there is an app for everything. I had to ./configure, make, make install libdvdcss too, but it gave me no pain. I also prefer Gnome to KDE, but I already have Gnome in my debian box and I wanted to try something different. But if you like Gnome, my advice is to look somewhere else (although it's possible to install gnome using some .tgz). It comes with fluxbox, xfce...if you are into light desktop/window managers.
The thing is I was expeting a challenge and, surprise, everything went OK right from the start. Very pleased with Slackware 12.0. It is not a beginner distro, but considering my skill level, it is nice enough to give it a try even if you are unsure about your linux knowledge and the install//config is painless, from my point of view. Kudos for Slackware, a pretty nice distro!