It's pretty irritating how it stops the movie to rebuffer and adjusts video playback quality based on network conditions, but that's streaming for you. HD will give you higher resolution, but the image quality is anything but crisp. The kid is using it a lot more than me, since image quality is less important for Inspector Gadget than for your typical movie.
Tried watching Wall-E simply because it felt more convenient the running the PS3, but it stuttered too much, and there was seemingly nothing wrong with my connection. Worst experience so far.