I've already expalined all coins with a hard cap, including bitcoin, will have a hard fork in the block reward because without hard fork miners will leave when the block reward is 0. A hard cap on amount of coins is useless, it's just commercial hype. A voting system is the best way.

At the bitcoin conference.

"As block rewards reduce in size, transaction payments may not be sufficient to support the ever-increasing mining costs. This could result in the need to resort to a constant block reward for perpetuity in order to compensate miners appropriately."