It becomes useful after contract ends. I.e. I did not hear that locked phones magically unlock themselves after period of a contract. Instead you need to call some number, hold on a line, explain to reps what you want to do, explain that you contract is over, etc and then finally get unlock code.

It will be way less hassle if it would be just unlocked from start.

ps: still have Ericsson T60i and Motorola RAZR Gold.. While currently unused, old and scratched, I can rely on these when traveling somewhere with GSM networks.