I'm not seeing the value in a 64 bit processor for the phone. I can see it for faster cryptography. But what phone app needs more than 4 GB of addressable space? The GPU is faster all on its own so we don't need it for graphics (very few developers will produce games that can only be played on the latest device).
It might make universal apps easier to write. Once and done for Mac, iPad, and iPhone? Dunno.
I would have preferred much improved battery life in the trade-off with performance, exactly what they did with the newest MacBook Air.
The 5C disappoints me only because it is not being sold at enough discount to the 5S, IMO. I need to handle one to see if it feels "cheap." The earlier plastic iPhone felt fine so I expect these will as well.
I do like the camera improvements. If you think the latest phone cameras are total crap, you're holding it wrong.
Show me your other automatic color-balancing flash, lol.
I use an even worse phone camera to scan documents these days and the phone is always with me, something even my tiny Canon S-series digicam can't say. Sure there is still a place for full-size (meaning 35 mm) cameras but most consumers are fully served by this generation of phone camera. Don't forget the medium format snobs always looked down their nose at 35 mm. Heck, the large format guys (I was one of those) did the same to medium format!