I installed Arch Linux on my machine after FreeBSD ports system were broken on my PIII machine (ironically hostnamed rocketfuel) for more than 3 weeks. Two distros contesting to rule rocketfuel were Xubuntu 6.10 and Arch Linux 0.7.2.
My first impression of Arch Linux is that it is an excellent distribution for that legacy hardware. I installed XFCE and my machine is flying now - blazing fast. The package management system called "pacman" is working very well.
Also, Arch is i686 optimized. Hence it can leech out last bit of performance out of my legacy processor. Xubuntu has software compiled for i386.
The drawback of Arch is that there are no automatic hardware detection while installation as one might expect with X/K/Ubuntu. I had to spent some time configuring my xorg.conf file.
Though there are some glitches with sound card (entries created by udev for sound system are required to be chmod'd to 777 for regular user to use sound card), remaining hardware is firing all cylinders.
It looks like Arch will rule rocketfuel for some time to come :-)