I have had both types and both run like crap when the lubricant dries out and work pretty good when grease is fresh.
I installed a SII bulkhead in my late IIa and did convert the bulkhead to the late IIA/III wiper system. It is a PITA locating the holes for the wiper shafts and locating the hole for the drive shaft tube/ wiper motor on left side of the bulkhead. I would get a good pattern to do these if you go that way.
Usually if you disassemble the gear box side of the individual wipers, clean and replace with new grease they work fairly well. Also have the option of hand operation if all else fails.
THING 1 - 1973 88 SIII - SOLD
THING 2 -1974 88 SIII Daily Driver - SOLD
THING 3 - 1969 88 SIIA Bugeye Project
THING 4 - 1971 109 SIIA ExMod - SOLD
THING 5 - 1958 109 PU
THING 6 - 1954 86" HT