I just bought a 128gb iPP 9.7 LTE form a guy on swappa. I have the identical model, color, etc from best buy. The one from best buy weighs 445 grams. The one from swappa weighs 449 grams. Small variation, but I can tell the difference. iTunes accepted it and I was able to upgrade to 10.01 just fine, but I'm still curious about what would make them have different weights. Any ideas?