In concept, SS Guardians. They're cooler looking design wise and are closer to being sentient beings. There's also the hopelessness the player feels when being chased by them because you can't fight back and one hit will kill you. It is stressful when you run out of time or awaken them.
However, that doesn't happen very often in SS. In my experience, the tears were never hard to find or spaced out far enough that I was in danger of running out of time. I think I awakened the guardians twice or three times my first play through.
You know what happened a lot in BotW? Got absolutely annihilated by a Guardian. They're a bigger threat in BotW, and are terrifying at the start of the game when you aren't able to defend against them. I also think that, unlike SS Guardians, the ability to hide from BotW Guardians makes them a little scarier. You know how to get rid of SS Guardians, get another tear. But BotW guardians, if you aren't strong enough, you have to hope you can run or hide behind some ruined building.
