I'm no file system expert but the way I understand it reiserfs is suppose to be good at handling a lot of smaller files. I use to use it for work (source code=lots of small files) but never saw any real benefit so I switched back to ext3.
Now JFS and XFS are suppose to be the opposite, good at handling (extra)large files. The delete issue is the most obvious example. When I first started playing with Mythtv I started with JFS but got burned pretty bad (may have been my mistake), so now I use XFS. No problems so far.
Here are some links with more interesting info:
http://linuxgazette.net/102/piszcz.html
http://www.debian-administration.org/articles/388/printhttp://lwn.net/2001/0830/a/jfs-comparison.php3