I have 4.5.1 running on iPad3 (x2). So far I've not had difficulty with faders but EQ has been intermittently unresponsive, much like how you describe.
This is way out of my sphere of knowledge but I was under the impression that the iPad app wasn't such a huge resource hog and that the DL was doing all the heavy lifting, am I wrong in this? What is MF doing other than graphics which are less involved than most preschool games and sending control messages over WiFi?
Happy to be put right on this.