IMO, for real (not fantasy) baseball, true maturity by a young player is a great batting eye. because anyone can have natural power, but if you can make contact and not swing at the outside pitches, you will be a good player. cintron is very mature for a 24-year-old callup.
however, despite only 16 K's, he also has only 18 walks. so basically, he's been swinging and hitting. hell, i'll take it.