I purchased the Marco Polo recently, mainly because of the worries about cellular issues, size, weight and battery time between charges. It's pretty slick and if I ever lose interest in drones, I can put it on my dog's collar or in my wife's purse. Initial investment is 2x Trackimo, but nothing further. It comes with its own receiver/locator, so nothing else is needed except a spot of velcro on the side of the drone. It's beacon signal does not interfere with the drone. I'm happy - if I remember to use it.