Plunger, because of more ball control. Auto-launch with a button isn't much fun.
Plunger because usually the ones with the buttons always plunge my balls for me when I don't want them plunged yet. (Some "transistioning" games with a real plunger do this, but still, not as many of course as the plunger is like 100 years old)
Option C, Gearshifter on my Getaway. Guess you could consider it a button in function but more thematic to the pin. Probably similar to other themed launchers like pistol triggers, etc.
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