One alternative I’ve heard mentioned is a token bonding curve/ICO hybrid:

You have a regular fully funded single curve with a target price. When the target price is hit, the token bonding mechanism is disabled. At this point, a regular ICO sale is triggered where the sell price is the target price + some markup. In this way, you achieve 2 things:

1. Because trading stops at a certain price point, you (the owner) can withdraw all funds on the token bonding curve
2. Because the ICO sale price is higher than the token bonding curve price, early adopters who bought during the bonding period are rewarded, despite no longer being able to trade their token in for eth.