I used to own ipad 3 but I found the UI very limiting so sold it and bought nexus 7. I must say the nexus 7 is the best tablet till far I have owned in tablet world. The ipad is a good tablet but not the best tablet. Its quite a massive tablet and pretty heavy.
Sure the display is great and there is a healthy ecosystem of optimized apps but other than 2 reasons I didnt find any reason to keep this tablet for my daily work use basis. I cant really find a compelling reason to buy the ipad series hoenstly you can better go with an android market or android tablet.