mechanical: cheap, simple effective, can be 2 or 3 wires.
Optical: can be triggered by stray light. Interrupters don’t always work as expected (many materials are UV or IR transparent), needs power, most are 5v some 12v. Works ok.
hall : most complicated board but simple to use, needs power 5v, works fine, needs a magnet to detect on the other side.
Basally they are all interchangeable and work ok. I would avoid Optical if you work anywhere the sun can hit it.
Lots favour the hall on the Z axis as it easy to tune with the potentiometer.
Edited 2 time(s). Last edit at 01/03/2016 03:06AM by Dust.