KLX110R vs CRF110F vs TTR110E

Hey guys, I am looking into upgrading my son’s ride as he has gotten bigger and would like to know your opinions on the above models. He is 9 years old and is upgrading from a CRF50F. I know these are all great brands and we should probably be fine with whichever way we decide to go, but I just wanted to see if there is any thing that might sway me one way or the other. Thanks in advance for your input!