The FF9 characters looked like children for a reason... they *were* children (Zidane and Garnet were 16, IIRC... last I checked, adulthood was considered to be at 18)

All of the games have their pros and cons IMO, except FF7 which is all pro (Not really, there's the poor graphics and poor translation)
I'd agree that FF9's end boss was the lamest fabrication of an end boss ever - but I found the story itself to be one of the best of the series.