We have been using them for years. (Savaria actually has it as an option now for their Lulas and Chairlifts, they are junk) . We do use a crane controller. We have Emergency stop buttons, as well as a key on/reset that times out. We use a four button with up and down being just that and north and south being the safe" buttons. The base unit defaults to the shut down mode if it loses signal from the handheld. Stay away from the Chinese junk ones, they share frequencies. If you get a good quality one like Remtron or Magnetek you get assigned frequencies/channels. We have done up to 4 car groups with no issues. Limit however is around 150', so sometimes we need to hang receiver mid hoistway. And keep spare batteries in your gangbox, they don't give much warning when they need changing,
