Upgrading from FTTC to FTTP

Has anyone done the upgrade from FTTC to FTTP?

Do you have to be in one of the NBN supported suburbs to do the upgrade or can anyone in any suburb be able to do it? (given you jump on one of the more expensive plans)

Also I hear that FTTC has a theoretical maximum speed of 100/40. Any horror stories around paying for 100/40 but not getting anywhere close to that?