I have both an iPad 2 and iPad mini. I like the mini better due to the incredibly small size. I now travel with it exclusively.
The iPad 2 is nice, due to the larger size, but I find that it's double the size and weight. To me, that's no advantage.
I purchased the mini with cell service, just to get the GPS feature. The 16gb base model does not have GPS. And, I use it as a backup navigation for my Cessna. Works wonderfully.
I do use the iPad 2 around the house, and when I need to display "maintenance manual" pages when out in the hangar. It's better for that.