I'm not a large volume blu-ray viewer, by that I mean I rent probably 2-3 new movies per month. I have a BDP-1500 and back when I bought it there were all kinds of warnings about having to upgrade the firmware in order to play new movies, and said firmware updates interfering with viewing other movies.
I can honestly say I have never touched the firmware that the player unpacked with, and I have never found a movie that it couldn't play. Am I just lucky?