They are taking over in the big cities already.

But don't be too quick to label them as safer. They are not. Their props are as lethal as any that turn. And plugging in the batteries in most setups exposes the flyer in new ways that most aren't used to. I've seen a number of them start up unexpectedly. It usually happens with people who've not yet learned the safe ways to arm the systems. Sometimes it's done by people who have no understanding at all with the systems, but sometimes by people who just aren't used to doing things that way. They really aren't safer.

But by golley, they absolutely are cleaner. And very very quiet.