If you have a 3G IPad you will find the GPS works fine. I use one in a 109 with no problems and have never had a dropped GPS signal. Typical GPS lock on is under 5 seconds. If you are in the UK I would look at Memory Map with CAA charts. We also have full ordnance survey coverage which has an excellent search facility.
Also worth considering is the Jeppesen app. Aeroweather, Notam, Theseus etc
Battery power is excellent.
Great for reading the newspaper on long legs and films when you are waiting for your pax!
In short it will never be far from your reach......
Bilbo