[ziszis]

The trade-off is going to be different for different people.

If being able to take movies with you on your commute or on the plane is important, it doesn't matter if Netflix's UI is better since it isn't even accessible.

If on the other hand, you are mainly interested in streaming at home or where you have Wi-Fi, you could debate the merits of Netflix UI vs. Amazon UI.

Amazon has found a way to make any advantages Netflix has irrelevant for some set of users and some scenarios. And it looks like it is hard for Netflix to follow. The question is whether it will drive enough trial and adoption for Amazon.