We bought the Disney Princess set and it didn't work at all. We received the Barbie set and it seemed to work better when were close together, but when we moved more than 15 feet apart the sound was not coming through one receiver. Maybe ours is just defective.
For Christmas we got our children the cheapest Uniden set from the electronics section of Walmart for about $18. It is 1000 times superior to any toy set. It has a 10 mile radius (supposedly) and multiple channels. When our daughters opened it they had no interest in it because they aren't pretty, but maybe that could be helped with stickers or even paint.
DON'T BUY TOY WALKIE TALKIES, THEY NEVER WORK.