It happens that for any check and analysis of video stream for its very low details and compliance as for h.264/AVC and more standards - not many tools available.
Let me count (without any priority):
and not sure if missed any other one.
Are they any useful?
To the good extend - they are unique in the functionality!
How you going to prove that your implementation is good and stable enough without such tools?
I've been getting very good experience with StreamEye as it helped to solve several very tricky bugs related to NAL's, SEI's, where some players were able to decode and show encoded streams properly but not the others, Windows Media Player was refusing to play but QuickTime...
It will be interesting what will happen with the next standard - "H.265"