I would say ... maybe. But the main issue is that LOD is impossible for the iPhone 5, due to the lightning port only being able to carry digital. This means that a DAC MUST be present in the converterplug, and I don't believe that a decent DAC can be had at either 15 or 25 GBP.
With LOD, you use the DAC inside the iPhone 4s (or ealier) - but those days are over. :(
So; maybe a really nice DAC will come out, for the Lightning port - but to me it doesn't matter unless they can squeeze it into something in the size of my FIIO E02i Rocky.