Also the 7 Sevii Islands, and get one of the 3 legendary Johto dogs/cats at the end. Besides, the game is much more easy than the original versions (it was made for newbies more than any other person xD)
Oh right, they moved Moltres.
I always loved finding him in the last stretch.
And the tea thing I remember.
I always go to Celedon's roof, get a drink and rush down to go into saffron, but the guards stop me. It took me a while to find the tea, even after playing FR/LG a bunch of times
A BIG addition to the games was the introduction of Special Attack and Defense stats. Chansey is now no longer the ultimate Special wall and attacker (Just wall), and the entire battling aspect of the game has since been shifted into another completely-different dimension.