Just to clarify you can use this on any GSM carrier which uses a sim card like AT&T, T-Mobile, H2O, Simple Mobile and so on as long as the carrier uses a Sim Card. Cannot be used on Sprint, Verizon etc... Because they do not use sim cards. So the person who asked for a clean ESN this does not apply to this phone because ESN carriers do not use sim cards so it will not work for that person.
The unlock makes it so you can use any carriers sim card and the jailbreak can allow you free aps free music program tweaks as well as full customization,
And is it hard to customize and everything? Does it take a lot of work to customize and can youstill use itunes and stuff that you use with one that isn't jailbroken?
It's tricky to figure out but once you have it down it's super easy, ( google is a great help with this) and iTunes and app store will remain the same... Although you won't find yourself using them...
Esn? It's not jail broken right now, but if someone wants it unlocked I would have to jailbreak it... But right now you can just put your sim card in n you're good to go...