The rooftop was a fun little adventure, one of the best in the entire game IMO. I didn't find the sniper rifle to be very useful just in a general sense since in this game you are very rarely in a situation where you can see your enemies from afar. If there ever is a point that this will be the case it is telegraphed to you by putting a platform somewhere ... "oh, i wonder what this very convenient vantage point that leads to nothing else is here for?"

Shotgun all the time!