Like previously stated they can be "high strung" as juvies but they do tend to calm down. If he has multiple to choose from try and find one that isn't so nippy.
Personally I love carpets and think they are a great next-step snake after a BP.
another thing to keep in mind is that they are a more active and curious snake than a BP and will react quicker as well. if startled they will flinch and rise up vs coiling into a ball. I have also noticed they "lunge" kinda a half-ass strike without opening their mouth if you startle them sometimes.
Just being confident with them will do wonders though. and they do have a strong feed response so make sure they know your not food before you stick your arm in their lol.
Good luck and I hope you can pick one up!