I absolutely love my Netflix-streaming Roku box. If I have any complaint, it's that it doesn't use enough bandwidth! They stop at 720P high-def and my set can only sync up at 1080i, so I don't get to use all that high-def goodness.
But when they remove that restriction, my internet provider is ready to serve up all that bandwidth!
Get a device that streams VUDU HDX titles if you want better quality with more bandwidth. Or get XstreamHD(if it ever launches)