Many builds have used a microswitch with a plunger, but the microswitch can take a pretty bad beating, depending on how it is mounted.
This. I think the micro switch would get hammered pretty bad if the plunger makes direct contact with it. You could rig it so that the plunger engages a switch when it is pulled back like in this old thread
http://forum.arcadecontrols.com/index.php/topic,7361.msg53235.html#msg53235Something to bear in mind with these setups that use a microswitch is that although they have a "real" plunger, they effectively reduce it to a "button". You could just get one of those large "launch ball" pinball buttons that were found on later pinball machines
http://www.pinballlife.com/index.php?p=product&id=1685On my pinball build I have gone with the V2 from virtuapin, but can't really comment on how good it is yet. I suspect it is better than the nano tech because it auto calibrates everytime the PC is turned on. I think I read than the old version regularly went out of calibration and was a pain to fix.
The advantage of these expensive plungers is that they adjust the power of the shot based on the position of the drawn back plunger (distance). The microswitch option adjusts the power based on how long (time) you pull it back for. They should be more "authentic" (and I use that term pretty loosely), but whether it is worth the extra $$$ is up to you
