You have touchwiz. Enough said. I love touchwiz on the GS3 and don't mind it on the GS2, but touchwiz is complete and utter garbage on Samsung Tablets. Plus, you wont see Jellybean for months. Then after you get Jellybean you simply will never see what comes after because Samsung will and always does drop support for phones after one major update. Asus build quality for exceeds that of all the Samsung tablets I've owned. I don't knock SuperAMOLED + because that screen tech is the best out there. And if your buying a tablet today, your getting straight ripped off paying $500 for a skinned ICS 7" tablet.
Lol that all being said, if you already have a 7.7, its definitely a waste to buy another 7".