No difference (technically) between a Sim free and a sim locked phone.
The differences are in price and how transferable the phones are :
1: The price ,sim free ones are typically more expensive as the sim locked ones get discounted by the network as they tie you into a year long contract or somat like that
and
2 : You can pass a sim free phone onto anyone....they put their card in and away they go...so there is a certain amount of resale value there. Sim locked ones you can't ... can only pass onto people who have sim cards for the network the phone is tied to.
But from a Pure case of 2 phones the same make and same model they should be capable of exactly the same set of features.