I've tried both iPad and iPad mini with a GNS 2000. I have had drop outs on several occassions, I fly a mixture of high and low wing aircraft. The worst problem to me though was getting the GNS and iPad to talk to each other in the first place. Other people at the club I fly from have had the same problem. It could take ten minutes or so sometimes using various switching on procedures to get the thing linked up. It's not a problem with Skydemon or the 2000, it seems to be an iPad thing.
I then about a year ago just for the sake of it tried my iPhone 5 suckered to the perspex so that in line of sight it's just to the left of the left most instrument on the panel. It works a treat. I've never had any problems with it at all. It's convenient, doesn't hang on the yoke with builders scaffolding and I just unclip it and shove it in my pocket at the end of the flight. I know it's a smaller screen but once the newness of faffing around with SD on the iPad wears off you find out that 99% of the time you just need it for the magenta line. It's plenty big enough to read the geo ref plates that come with the Pooleys subscription for when you are taxiing around at an unfamiliar airfield. I haven't used anything else since. You can of course charge it in flight as well for the longer trips.