I don't find Super Metroid that hard, but maybe because I'm from the old school
I always played hard games since I'm young, NES games were very hard (but I have difficulties at playing them again now, I became too lazy because of easiness of actual games
).
I completed Super Metroid many times, but I'm always looking for 100%, so I never ended it in less than 3hours.
after my first time finishing the game, I looked at a game guide to find missing items, now I don't use it anymore (don't use a guide before finishing the game by yourself first, it will give you even more satisfactions)
I'm always amazed at looking Super Metroid in assisted video, especially boss battles.
I'm currently playing Metroid Zero mission again, It's a nice one in the series.
Next one will be Metroid II, the only one I never played.