I agree with
I really like auto-join but it does have limitations with 2 fleets in the same grav well
I've only ran into a problem with it when your trying to group two fleets in a grav well, and add ships to either of those fleets. The other situation is when your in a battle and you want to send re-enforcements. Ultimately, I think auto-join works for most of the time, however, it'd be nice to see an option in the ship's tactics where you could assign it to a particular fleet, no matter where it was at, and maybe it would jump there, or just join if it comes "upon" that gravwell....