Minimalist is harder than 100%ing depending on the game. For OoT, 100%ing seems harder to me, but minimalist is far easier (just requires magic management, ahaha). For TP, either one to go, I find 100%ing the game to be a bit harder, if not because of the many heart pieces scattered across the empty land of pre-tech Hyrule. But for Majora's Mask, honestly both are pretty challenging, if not because of the 3 Day system.
Here is a bit more detail, for the three games I chose.
TP Minimalist - Really, REALLY easy. All it requires is L/Z-targeting, sidestepping, and that's all for TP. You can literally run through the entire game without a shield, extra hearts, death, and/or bottles.
TP 100% - Moderately hard. Requires a map for all heart pieces if you don't remember them, and beating Rollgoal all the way will eat your brain cells if you're not experienced with that sort of game/the sensitivity of the controller.
OoT Minimalist - Sort of like TP, but the enemies can actually one hit kill you (Iron Knuckles, anyone?). Oh, and do beware of the Redeads, because if they catch you in their gaze and are in a group, they can murder you. It's almost impossible to avoid those, haha.
OoT 100% - Really easy in some respects, because the world size is compact, everything is easy to get to. But, getting some heart pieces can be a pain, especially in Lake Hylia where you THINK you can jump to a ledge, but it's about 2-3 inches away.
MM Minimalist - With the great amount of diversity of enemies between dungeons, not having a shield can get you discouraged.
MM 100% - Some heart pieces are troublesome to get, but it's easier than Minimalist.
