1900 PF has characters, Cinderella and friends, I think at dinner. It is a buffet with good food and a chilled strawberry soup that was great. 1900 PF is quieter and more elegant than Ohanas.
Ohana's is family-style, where they bring lots of food to your table. There are coconut races and other fun activities for the kiddies. There is alot of meat if you want it, but we dont eat very much meat but loved the appetizers, sides, and dessert. Ohanas has a livelier atmosphere that 1900 PF. We really enjoyed the food (especially the amazing dessert).
The atmosphere in each is unique, and the food is quite different, too. I would suggest checking the menus out at allears.net or another site.
We have viewed the EWP from the GF (from our room) and it passes right up next to the hotel. Haven't seen it from the Poly (yet).