I dont see a reason for the upgrade unless you want the latest and greatest. I bought a K2 for myself and got the K1 for my sister from eBay. While the K2 is a little faster it is not enough to warrant the upgrade. If I would have had a K1 to play with initially I would have gotten that one and saved myself some money.
If you do decide to sell the K1 let me know. I am in the market for one for my sis in law
