I leave and come back all the time. Being modular and small are valuable in creating bootable CDs and USB Flash drives. So I frequently experiment with TC, and almost used it as the basis for a turnkey "test and clone" system. Almost. Instead, I added my scripts to Patrick Verner's Parted Magic which gave me the preconfigured OS plus a set of related and useful applications in a CD-sized package.
My daily driver for years has been the minimalist CrunchBang. It has evolved with so many customizations that moving to standard Debian Wheezy made more sense when CrunchBang also moved to wheezy. I am still an Openbox/Tint2/Conky fan, and can squeeze my wheezy installation onto 4GB. Lately I am back at TinyCore for the dCore project (small, modular, AND based on Debian) to see if I can recreate my desktop to a smaller USB Flash drive or maybe even a CD.
I have also like Porteus 2.1, and managed to recreate much of my Debian desktop installation in 600MB. But being based on Slackware, there are fewer pre-compiled packages. To get what I want frequently requires building it myself. But I am lazy and only willing to do this for one or two packages. I prefer "off-the-shelf" packages so I don't have to debug the builds or keep up with updated sources. For the moment I have drifted away from Porteus, but recommend it nonetheless. It is compact, modular, can be loaded entirely in RAM, and compatible with the all Slackware (Slackware/Slacky/Salix/Alien) repos.