It never reliably functioned as a daemon for me. It would just stop checking for messages randomly after an hour or two. And if you give up on it being a daemon

It never reliably functioned as a daemon for me. It would just stop checking for messages randomly after an hour or two. And if you give up on it being a daemon, then it's horrifically slow because it's doing full syncs all the time. I ended up having a script running out of cron that would kill and restart the daemon process every 30 minutes so that I could get reasonably fast incrememntal updates but still have it continue to work properly. And then it started losing track of what the server looks like. If you delete a label on the Gmail side, then of course offlineimap wants to recreate it. For a little while, it was tolerable to stop offlineimap, delete all the local metadata for a folder, go delete the folder from Gmail, and then restart offlineimap, but eventually that stopped working too, and it was recreating deleted folders on the server that I never managed to find a reason for. isync just worked exactly how I wanted to after spending a bit of time setting it up, and it's been pretty solid since then.