I think the glow is a great choice if you read in bed or poorly lit environments. Play with the one at the store. I like the fact that the Nook is easier to grip, making it less likely to slide out of your fingers, something that happens to me now and then with kindles. I don't like covers - they add weight. I just have a simple cover that I made myself for storage or to prevent scratches in my purse.
As far as returns, I can't help you there. I don't know anybody personally who has ever returned a Nook. They appear to be more resistant to damage than the kindle (both me and my bro had to replace kindles due to damage even though we are careful).
I have a kindle keyboard, 6 inch kindle, Nook ST and am testing a Paperwhite that I bought for mom. I would have bought her a nook glow if I had known the price was going to drop. I'm so spoiled with that added lighting, I'm buying myself a Nook Glow before the end of the year.