Netflix, amazon prime and hulu user here.
Movie content will overlap to some degree but mainstream content seems to be complementary amongst the services where some shows are exclusively available on one and not the others.
Our home has the Western Digital TV Hub, Roku 3, Plex, XBMC, ipads, ipods and a few other streaming devices. We also have 2 Verizon FIOS cable boxes servicing multiple HDTVs in our media wired home. With all that said and done, its really all about the content.
Last week, i watched the netflix produced season of Arrested Development and last night, Serenity after many many years. In some ways, HDTV is just spectacular, but in older films, i find it cheapens it by exposing all the flaws in the stage and props as it was never prepared for HDTV. The original star wars movie sets had some really poor sets where it otherwise went unnoticed under standard def. Its one of my concerns revisiting the Star trek movies, now on Bluray. HD however is the wave of the future so as Herns suggests, select hd when available. The latest movies just blow your mind on the level of detail possible. Any one waiting for Pacific Rim?
"I am Groot", the faithful protector