This is probably the best switch I ever used.
Functionality
The same as super switches (Fender, or DiMarzio). This switch allows you to do virtually any combination of pickups wiring on your guitar (with HH, HS, HSH, HSS, SSS pickups).
Operation
The smoothest switching of all switches I ever used (including Fender, Oak Grigsby, DiMarzio and Switchcraft). Absolutely quiet and precise. I am now seriously considering to replace all switches on my guitars with that model.
Remarks
Schaller says Model M is mostly for HH, Model E is HSS and so on. Not really. I am using Model M on HSH and HSS.
To those who say "no instruction", or "no schematics", or "crippled instruction", or "I have X years of experience, but cannot use this switch" - if you cannot understand (ABCDE)F, (GHIJK)L, (MNOPQ)R, (STUVW)X, then this switch is not for you. But then again - Fender or DiMarzio, or Oak Grigsby are also not for you. They all operate using exactly same logic.
In that case, simply take your guitar to a luthier ;-)
If you want 5 way, quality build, extremely smoothly, precisely and quietly(!) operating switch - Megaswitch Version M is definitely for you.