If you buy online and the confirmation shows up on your mobile device with either a bar code or a QR code showing on your mobile device, you can go right to the touch-point and show the Greeter CM the code and they can do the exchange right at the touch-point for a hard card ticket. No need to go to a will call window.
Do be aware that sometimes a guest will be asked to show the credit card that was used to purchase the tickets. You can hold your finger over most of the numbers just so the CM can see the last 4 for verification. It's real random that it's asked for though, sometimes shows up on the CM's handheld device to verify.