Level 1 is pretty weak yeah.

Vaan's burst is fantastic, but outside of it, he can't equip Full Break and I can't make use of his thief abilities because I have none honed. Thieves are simply too scarce (when it comes to relics I have) for me to justify mugging skills.

He'll probably still show up on my XII teams though. Basch, Ashe, Penelo, Balthier and Larsa all have relics already. Ashe has her OSB and her Teamheal, Larsa has his heal and hastega, Penelo has even more heals and dancing and Basch has his phys blink. The only one I could really see him beat out is Balthier, since while I have Balthier's burst... it's Balthier's burst.