I wrestled with the same decision.
After evaluating what was important to me, I determined my next device needed a great camera, Glance, Qi, and at least 32 GB. I'm on AT&T, which is why I didn't upgrade to the 1520 upon release since they halved the storage and removed Qi. I'm anticipating AT&T doing something similar with future devices, so I went the path of the 1520.3 a couple of weeks ago, which gives me everything I wanted. I figure if I have to wait for a similar variant to come out with future devices (should I stay with AT&T) I might as well enjoy the 1520 right now, which I am, immensely.