I bought my 3G iPad2 and installed SkyDemon on it a couple of months before flying my new Cabri G2 helicopter back to the UK from the factory at Aix les Milles. Approx 600 nm with no position drops during the journey.
Previously I have used the Skymap IIIC which was generally reliable but did on one occasion near Reims indicate that I was flying to the left of an Autoroute when I was in fact on the right.
On two occasions, out and return, in Belgium I did pass through a GPS dead spot where both the Skymap and Garmin GNC 250 dropped out. Both came back online a few minutes later.
Helicopters do have a very good view of the sky which may contribute to GPS performance.
On the odd occasion where I needed a little assistance I have found SkyDemon support very helpful.
It works for me.