My main problem is that because it doesn't gain casting or offensive combat features, it mostly gains utility. The problem is it'd be better to play almost anything else for those 15 levels, or maybe take Illurien for a few levels to qualify for some class (I'd take usually around 5-7 levels, 7 if I wanted flight). Otherwise I'd just use it for a 1 level dip to get Outsider status and an NA boost...