The pledge amount and delivery date.
Earliest supporters receive a Go Journal for a lower pledge amount and will receive their product sooner. This is because of the production schedule for Go Journal, and to offer a special thank-you to our earliest backers for their support.
There is no difference in the product received between Earliest and Early supporter tiers.
Yes, very portable. It weighs about .75lbs, (.34kg), and is about half the size of US printer paper (size A5, to be speicific).
I spent a year traveling the world out of one small bag. It was important to me that this product be thin and compact enough to take with me.