I use the QuadLock and have been so delighted, I have bought another, and will buy even more for others of my bikes.

You don't have to stick the phone mount to the phone. I bought a back cover that the phone slips into, and stuck the mount to that. It means the phone (Samsung) can be swapped between that back cover and another flip cover I have.

I do randonnees, and my phone will last a century if I use the display sparingly. But then, I have the route instructions printed out in traditional form and on my handlebar bag. To boost for events over 100 miles, I use a battery pack with 8000mAh capacity. I have done two 400km distances with that arrangement and I am confident of doing a 600 and maybe even a 1000 with the phone and battery pack together.

I've also looked at using the Bluetooth function to record heart rate, but haven't got around to getting the strap yet. Apart from that, I use Strava, and mapmyride to plan routes, and all has worked as I wanted. Plus, other advantages over a simple bike computer is that I can take pictures, amuse myself at rest stops on the net, or make a phone call as needed to let organisers know that I have finished, etc.