content: Second screen reminds me of the Edge on Samsung's phones.  If I like the rest of the phone I'll accept it as a plus but it isn't a deciding factor.  And it can't replace smartwatches as the purpose of the watch is something unobtrusive that notifies you as opposed to holding your phone up to your face.  Most people have a large number of their texts that they either do not need to respond to or they can respond in simple yes/no fashion.  My watch lets me do that much more quickly than I could even get my phone out of my pocket.