Maxred. Yes an ipad2 coupled with gns 5870 works perfectly with skydemon or air nav pro. I don't believe the ipad3 is worth the extra money unless your into gaming on the iPad. The performance between the 2 is almost identical as the extra graphics power in the iPad 3 is mostly consumed running the retina display. (google it you'll see what I mean!) From what I've seen of others in the flying club many complain about the internal GPS performance and have since bought gns5870's anyway for confidence reasons more than anything.
It makes most sense to me to buy the ipad2 16gb wifi and gns5870 for the same money as a ipad3 16gb wifi!!
Hope that helps!