Warren in Lancaster, PA
I guess I would give a slight nod to the cap irons on the beech planes, but both are plenty functional. I usually remove the screw completely when sharpening. With the Bailey design the cap iron is thin enough and the screw short enough that it is ready to fall out anyway when it is loosened. Some 19th century cap irons have an extra nut welded or braised to the lower side of the cap iron. This nut fits in the slot of the iron. For the cap irons in the Seaton chest (1796) the hole in the cap iron is punched through from the lower (concave) side. This leaves extra material on the far side so that when it is tapped you get a longer threaded hole. There needs to be a little hollow on the underside of the wedge to accommodate this protuberance.

I looked at the Hock cap irons in 2009 and wondered if they had enough curvature for them to be effective. Ron told me they could easily be bent