In the Debian stable distro (at least), ext3 directory indexes are not enabled, meaning new users have to do a init=/bin/bash or edit their init scripts to do a e2fsck -Df after enabling the option with tune2fs if they want these.

It seems that this option is normally enabled by default these days, is it a conscious decision to not enable it?

(Personally, I'd prefer reiserfs any day, but I'm giving ext3 an extended trial.)