Jim,
The iFly GPS software is equally-yoked on both the iPad and Android tablets. It's our goal for them to be like-featured, however there will likely be some features possible on Android in the future, like outputting NMEA data via a USB port, etc. Apple currently does not have a USB port so this would not be equally possible. There may be some wireless option as an alternative.
Another benefit with the Android is our software will support loading to an external SD card, so you are not as memory bound as with an iPad. Make sure you buy a 32gb or 64gb iPad if you go this route. Additionally, you have some nice and bright models of Android like the Nexus 7 (2013) version and possibly the Kindle Fire HDX (pending us getting on the kindle store or making a downloadable file).
On the flip side. With an iPad, you will likely find more Aviation Specific mounting and power accessories. Also the new Mini and Air with the Retina screen are good and bright too, but not as much as the Nexus 7 or Fire HDX. Keep in mind, none of these iPads or Android will compete with the 720's brightness, if you have a super bright cockpit.
It's probably more dependent on which ecosystem you are more tied to, if at all. iTunes & App Store versus the Play Store, as App, Media, Book purchases, etc. from each store do not transfer over to the opposing store. It's just a consideration to make if you bought a lot on the Play Store or Apple App Store.