I prefer AIO even though it doesn't dispel ran like RainX. RainX gives me glare and wiper chatter. RainX also has the edge on shedding frost. But I hate the fact that I can't see too well with it.
RainX is very good, I use it every 2 months or so, my wife would complain that her car wipers weren't as good as mine. So I applied the RainX to her windsheild and she is very impressed, and insists her ford fiesta is now every much an equal to my 3 series! Well who am I to argue with that ?