Help unlock codes do they last

[Tbloke]

if i get a sensation xe that has been unlocked using a code by one of these guys you see up the local high st will it stay unlocked if i do a factory restore or will it have to be unlocked again? and will it upgrade to ice cream sandwich ok without re-locking

 

[hopey]

It stays locked and wont reboot to previous op
norman

 

[murzz]

I unlocked my XE with a code purchased from the web. I can confirm it upgraded to ICS no problem and no re-lock