I do. Not all the time, but every once in a while. I used to have a script for doing this with CVS, but I have no idea where it went. I also couldn’t find anything that did exactly what I wanted, so after some futzing around, I made my own. It’s simple, it’s rough, it’s ugly, but it scratches my itch. It takes a FAS username, and clones all packages owned by that FAS user in the current directory. It takes an option to run fedpkg prep in in each check out as well. You can find it here.
I’m mulling adding features, and am open to suggestions and patches as well. If you find it useful, let me know!