I agree that the 6" K2 (as was the K1) is a bigger device. But as much as I hate to admit it, the keyboard is pretty useful...but nice for me the Kindle file system is horrible so I don't see me keeping my new K2 more than a week or so just to say I tried...my heart belongs to Pocketbook I think...but I, well, we could not pass up the deal I got from Amazon & Audible...
I really think from a portability standpoint the PB360 is the best case design of any ereader device. It's THIN plus it has that hard-shell cover to protect the display. When you look at the picture someone posted of it compared to a CD case, the perspective becomes really obvious...and advantage Pocketbook.