One caveat is that they have, have, have to be kept in good working order, which doesn't bode well for location games / casual routers.
There was a Revenge from Mars at a local watering hole down the street from me. When it first went in, it was getting played non-stop with no ball save making money hand over fist. One day, the SOL hole start shooting it SDTM, and the owner didn't fix it for a month. I haven't seen anyone play it since.