In reply to itsThere:
> a new non-smart phone will last way longer but wont have much difference in terms of signal.
iPhones had a terrible reputation for poor RF sensitivity; they were 16dB down on equivalent Sony models at one point. That corresponds to a big reduction in range (depending on the RF propagation model you use; assuming the commonly-used r^4 urban model, it's a factor of 2.5 worse).
I'd hope that they've improved that in recent models...