Im a long time android user (G1, mytouch, Samsung Galaxy S, Nexus S, myTouch 4G) here are my thoughts:
- Touchwiz is so horrible that the argument should end there (Assuming this device has touchwiz, I doubt it will be stock android)
- Super Amoled is great for video and games, awful for text. I would say retina beats it overall.
- Samsung phones are battery hogs. Be prepared to always require a 3-hour mid day charge if you use your phone often. Vacations are tough on Samsung phones. You'll almost need to buy a second battery.
- Good luck every getting an Android update ever, if not it will be 6 months behind. Think about how many times the iPhone gets a software update over the life of a typical android phone. This is important when your phone is riddled with bugs like Touchwiz is.