I disagree with ragnar. Vpip/pfr takes far less hands to develop better reads than aggression. That said 15 hands is still too low for both. I really can't but AA/KK/TT/AK in his range though and I think Ax/FD/KT/worse hands/air are betting out more often because people like to slowplay. Either way you are committed but I think he has air a lot less often than other hands so I'd just get it in.

As for in general, I look at postflop tendencies. Since most unknowns/bad players slowplay I give their donks a lot less credit, especially if it's a minbet or close to it.