We have had an awesome experience with iPad 3 and our router (in signature), I’ve run even whole shows, even whole day (12 hour straight!) with my iPad, mostly next to T112. I am gonna try the iPad 4 with new MixPad update soon but I expect the same result as with iPad 3.
I always try to position the router on the right place, away from iDR, away from speakers, away from wireless mics and I always get great results.
Whats your router, whats it’s settings? What firmware and Mixpad version do you use? I guess we can help. 
iDR 48
T112
iPad3 + TL-WDR4300
