Please elaborate, I'd be interested to hear your rationale. IMO, they are both classics and the very upper tier of Metroidvanias. SOTN might be SLIGHTLY better then SM in certain areas (atmosphere, soundtrack, play control), but SM is a far more balanced and challenging game. Don't get me wrong, SOTN is amazing, but the experience system and surplus of overpowered weapons feels like permanent God mode.
The short version of my opionion is that:
more = better
my love for this genre is such that if the game has more content for me to explore the more I enjoy it. It also helps that the game plays better and has loot
