My daughter owns both but prefers her Adidas Ace ag/fg cleats. She said the turf cleats are a little more comfortable but felt she got a better touch on the ball with her regular cleats. Who knows. She can be fickle. Look around. There are good deals to be had on older/closeout models of turf cleats you could buy him to try and see if he likes them. My son was recently taking a Friday night 10-week camp. I knew he'd be training on turf but that by the time the fall comes around he'll need new cleats in a bigger size and practice/games will be on grass. He'd outgrown his other shoes from last season. He's only 9. Not sure where you live. Prosoccer in Pasadena has a lot of options. Found him a pair of Nike Jr Tiempo Leather Turf shoes for $20!! Normal price $50.