I'm only going to exchange Spirit Orbs for my Stamina guage. The stamina guage is more important in my opinion. It's responsible for your parasailing time, climbing, swimming, running and combat charge combos.
I'm not going to exchange Spirit Orbs for heart pieces. For defense, I'll wear armor and the armor upgrades provided by NPCs.
For extra health there are foods that extend your hearts so I'm good. I'm gonna memorize all these recipes:
Food - Zelda Wiki
I made up my mind on this because according to the 4 beast spoilers, those dungeon upgrades will make me powerful enough to deal with any threat.