10.0.3 didn't help with my GPS issues at all, if anything, it got worse (a 12.8 km run was recorded as 13.7 kms, so 7% off). So I've sent my phone in and hope for a replacement. This is not good, I've used iPhone 4, 5 and 6 for running over the last 6 years and never had so consistently bad gps as with the iPhone 7. I really hope it's just a hardware issue with my phone.