I hung a Jet AFS1000 today from 4 small screw eyes screwed into the bottom of the joists.

Afterwards I wondered just how well the hooks would hold, so I screwed another into a 2x4 and hung 50 pounds from it. (The AFS1000 weighs 60 pounds). It was fine until I pushed down with maybe 15 pounds of pressure and the hook straightened out. I thought it might pull out, but never expected the actual hook to fail.
So, I guess it failed at about 65 pounds.

If I have 4 hooks holding it, that is 15 pounds per hook, and I have tested them to fail at 65 pounds. That is a pretty good safety margin isn't it? I could replace them with bigger hooks, but don't want to make any bigger holes in the joists than necessary.