STR vs. VIT for leveling

[Rbstr]

Strength.
You get plenty of HP by being up on left-side stuff and the weapon. Hate is the hardest thing you have to deal with. There are a couple level ranges where it's nearly impossible against some synced players.
Anyone that gets hit with level-sync will be rocking the maximum ilevel for the dungeon. If you're in a level-appropriate dungeon it's very hard to do that yourself.

Vit is going to be most appropriate right when you hit 50 and again when you hit 60 since it's easier to hit content you're relatively undergeared for.