I just weighed my iPhone 4 with a case incipio ngp case. Its 5.9 oz. Ive carried it this way for two years in my hipster skinny jeans and all. (not a joke) Im pretty sure I can handle the lumia
I think phones shouldn't be focused on being light and thin. I rather have a phone which makes sense, like not having an irritating power button placement or a glass back, a very easily scratched chrome strip, or just a phone that feels like a toy.