DTD was not originally built as a Rainforest, they worked it into an existing building, but I don't think anyone can tell the difference if they didn't know.
We have done both, and I felt much more rushed at DTD. They do have walk up crowds there that AK doesn not get.
About PS........one year our group of 10 could not get reservations via Disney. Called RFC direct about a month out and only got them because I hold a Safari Club Card. This also gave us 10% off our meal. Card has paid for itself ($10 fee - years ago) over and over again. Good at all Landry restaurants.