+1. In addition to that, with the competion between WingX, ForeFlight and Naviator, you know they will keep pushing each other to just keep improving on what they are already providing. The cool thing is as they make these improvements, they provide their updates for free for people with current subscriptions. About a year ago I started using ForeFlight but swapped to WingX since it was a better fit for my flying. Both of these programs are awesome and getting better and better.
The other real plus for using the iPad is all of the other great apps you can have available, not just GPS.