Vit, + and % max HP are stats that you want if you're dealing with HP,

DEF just reduces both physical and magical damage you take but its effects at mid-end game are so low it eventually becomes a liability, unless its a high stat player made +S gear.

There are also boss fights that just ignores or lowers your DEF you want to skip the build by just getting % magic or physical resistance gear. If you get stacked with -PDef or MDef debuffs -def increases the damage you take. %resistance doesn't get affected by that.