The iPhone 5c is a well built device. For all intents and purposes it is a perfect replacement for the iPhone 5. If you were planning on buying a cost reduced iPhone 5 once the 5s came out, the iPhone 5c should have no problems filling that role. Its performance, battery life and camera quality are all on par with the 5.
Apples return to a polycarbonate iPhone design seems to have gone quite well. The iPhone 5c is solid, doesnt have any noticeable amount of flex and has a great in hand feel thanks to its nicely curved edges. I feel like the color options will go over very well with the 5cs target markets. I can see many users even preferring the styling of the 5c to the 5s in those markets that arent feature/performance sensitive.
Personally Id prefer the iPhone 5s simply because of its more modern platform, even if I were recommending a device for someone else not as concerned with performance. Supporting the latest ISA (which will probably stick around for a while) and OpenGL ES 3.0 are both important if youre going to be keeping your phone for a very long time and plan on using it for more than just the basic first party apps.
As I said before though, if your plan all along was to buy an iPhone 5 - the iPhone 5c is a clear substitute good. I dont expect that well see an even cheaper version, but I am excited for what happens when the 5s hardware waterfalls into the 5c replacement next year.
