Which Permissions plugin to use?

I apologize if this has been addressed, and I also apologize that I am unable to currently try anything (several users currently logged on to the server, and I don't want to kill it).
I'm totally new to Bukkit and have been using the development builds for MC 1.0.1. I learned about some permissions plugins, and I wanted to use them, but I saw that most were not updated for the development releases.
Now that the recommended build is for MC 1.0.1, what permissions plugin should I use? Do they *need* to be updated to 1597, or can I use some 1337 versions?

 

I use bPermissions because the author releases frequent updates. PEX updates less often, but has the most feature-wise. PermissionsBukkit hasn't gotten much love it appears.

 

I see bPermissions has been updated for 1.0.1, so that answers the question of whether it has been updated or not. Thanks!
Now, is setting permissions entirely done by .yml and group modification by console? Or is there some GUI to it?

 

You should try them all because its all about personal preference, but i like PermissionsEx