I find logs very useful, and I love Kildclient's ability to name the files dynamically. However, I have mine set up like so:
/home/user/rplogs/%Kw/%Kc/%Kc-%Y%h%d.log
If I use the autologin to login as a character, it works flawlessly. But if I don't, it results in something like this:
"Logging to file /home/user/rplogs/Gameworld//-2011Apr09.log."
The "//-" part isn't very useful. I realize I could restructure all this to accommodate the sometimes-missing character name, but if you're logging and using %Kc, I think it might be far more useful if it returns something like "General" or "Anon(ymous)", or some word that indicates there's no character, but results in no weird file paths like that.