I've said it many times, at a first glance, it doesn't seem like a massive difference. But live with one for more than a week or two, and you simply can't go back to the older iPad displays.
Same with me. When I got the 3 just after it was released, I gave the 2 to my wife. At first, I had some buyer's remorse because for the most part, at initial glance it looked the same.
But after the apps were updated for retina, and I got used to the screen, I went back to the 2 and realize how stunning the 3's screen really was. My wife still can't tell the difference, but we will leave it at that