I'd be interested in how the RFLKT thing (or the ELMNT) impacts battery life, it's a constant bluetooth connection which has obvious power implications, but modern phones are many orders of magnitude more reliable than Garmins, and if it could be made to work to your requirements (power, nav) would seem to be a good choice - cheap, as well, as it's just a display.
I have the running version of the RFLKT and it works really well - that the GPS chip in the iPhone is significantly better than the one that Garmin use doesn't hurt, either.
I'd be interested in how the RFLKT thing (or the ELMNT) impacts battery life, it's a constant bluetooth connection which has obvious power implications, but modern phones are many orders of magnitude more reliable than Garmins, and if it could be made to work to your requirements (power, nav) would seem to be a good choice - cheap, as well, as it's just a display.
I have the running version of the RFLKT and it works really well - that the GPS chip in the iPhone is significantly better than the one that Garmin use doesn't hurt, either.