Just went and played with it at the apple store. First impressions… looks almost no different unless you put a 4 next to it. It's is thinner and I kinda like that.
Picked it up an I was disappointed. It's very light and has a very cheap feel to it like a plastic android phone. The build quality is on point as always with apple but… it just felt cheap.
Noticed a slight improvement on the colors of the photos taken with the 5 vs my 4s. The colors looks more true and closer to real life. The panorama was nothing special. I have apps that can do it too.
The apple maps was total garbage. I hated it so much. The 3d feature is completely pointless. It sucked at everything when compared to google maps. Until google makes a separate app for the maps I see this being a deal breaker for a lot of people.
Overall I see no real reason to upgrade if you own a 4S. For owners with the 4 or less I would say go for it. The only reason why I would upgrade is to make a profit or if my phone stopped working. My wife has a 4 so I will eventually upgrade hers.