Sean

The 24mm F/1.4L II is just as likely to need an Auto Focus Adjustment as any other lens. Mine is a +3 on my 5D II. I don’t see the problem as being inherent to the lens. If you are going with the 24mm on a FF, your DOF is so great that you are only really going to notice any problems close up and at the wider apertures.

This is an excellent lens, my suggestion is to buy one. The only way I would say different is if you were thinking of the TS-E 24mm F/3.5 L II or the Zeiss 21 F/2.8 Distagon, and they are both manual focus. Either of those is a good choice if you have the need, but all three of those have their advantages.

And welcome to the forum.
Rick