Gentoo's "marketing" really sounded great to me and I was going to try it out (I have the 1.3 ISO) and got as far as stage1 or stage2 and was halted because I wasn't able to configure dialup connectivity at that time.
So I put it off and later ended up installing Slackware 8.1 instead. After evaluating the Slackware 8.1 environment, I decided to stick with it.
A couple of important reasons:
1) Slackware uses (virtually) vanilla everything and vanilla tastes great. I just feel better when I patch the standard Linus kernel (which arguably has more conservative options) myself (quite easy actually) to get the more experimental stuff like the O(1) scheduler, etc... Note that I have actually seen some problems with using these patches (try running several gfx animations with the ckolivas ck7_2.4.19 patch - similar setup to the Gentoo kernel with O(1),ll, rmap - to see what I mean) and am glad I can fall back to the stock kernel easily and cleanly. Most everyone these days seem to be running some variant of the Linux kernel instead of the Linus blessed one... same goes for KDE, etc... I can hear distant bells ominously tolling "Linux fragmentation".
2) Not having to learn YAPS (yet another ports system). Portage sounds great on paper but it also looks pretty complex. But that is actually besides the point. I have found it to be VERY easy to download a tar.gz, compile it the way the author meant it to be compiled (as opposed to being compiled for a specific distro), and cleanly create my own Slackware package which I can easily install and uninstall anytime.
See http://lists.q-linux.com/pipermail/plug/2002-September/021161.html for concise details. No ports system to wrestle with.
3) Slackware's philosophy has been very consistent throughout the years. Long time users who are familiar with it and understand its goals don't seem to have ever been in for a rude/unpleasant shock. Patrick Volkerding has stayed with the original 'least bloat' vision but at the same time has managed to put in all the modern Linux related core functionality in Slackware. Clean, lean and mean seem to be Slackware's watchwords and it shows.