I mean, you're not wrong, but I'm not sure if going from 500% to 540% from one slvl30 Exceed is amazing either. Or 700% to 740% with PF.
EDIT:Why not both.
Kamihime is a game about time, time, time. It will take you time to get better weapons for your Grid, so you're going to get both... eventually. If you're capped on your Water team, start working on other elements?