I was mostly using JFS when ext3 was current. I actually only stopped just recently, because I figured out that the weird disk problems I’d started having with installs weren’t hardware errors; the problem was that either the Slackware installer or Linux itself no longer properly support JFS. I switched to using ext4, and the problems went away.

But, on the other hand, my new storage server’s RAID has more than 200GB of filesystem overhead now.