Is cutting the arm off the Z-axis switch a good idea? We all know (or should!) that the repeatability of common spring-arm limit switches is crappy at best.  I'm looking to build &amp; install one of the precision height adjusters for the Z-axis limit switch, and noticed a post on some forum suggesting removing the arm and triggering the switch button directly (e.g. with a screw end).
Has anyone tried this, and if so has the repeatability of Z-homing improved any?
Edit
Sorry -- this is a stock Prusa i3, which depends on physical contact between the vertically-moving subassembly and a microswitch mounted on the frame.
While I haven't seen this on a Z axis for a printer personally, there is no reason it wouldn't work, and would improve your repeatability in theory. Removing the arm on the switch is taking away the lever. Going back to simple machine mechanics, the lever gives you a larger range of motion in which the button could be triggered, with the tradeoff that you get a larger target to hit. How much of an improvement depends on the exact switch, where the button is compared to the axis of the switch, and how long the switch is. 

My Shapeoko 3 CNC router has a switch for all three end stops that do not have arms, and my Original Prusa i3 mk2 has switches without lever arms on X and Y axis endstops, so there is is no reason it won't work for your i3 Z axis, you just need to make sure you can accurately hit the small button on the switch.