I only have streaming right now. Honestly, having all the Trek shows was a big incentive, and the episodes look great.
Can't wait for Deep Space Nine.
My problem with streaming is that I never know what aspect ratio it will be. Even on widescreen streams, I'm not sure that it is "correct" as much of it looks too cramped, to stretched or too severe. Sometimes the video quality is awful... as in Hunt for Red October.