I have a pixel (and previously a Nexus 5x) and I easily and naturally unlock using the fingerprint sensor on the back as I remove the device from my pocket. The

I have a pixel (and previously a Nexus 5x) and I easily and naturally unlock using the fingerprint sensor on the back as I remove the device from my pocket. The sensor is located within very close proximity to where my index finger naturally falls where doing so. Which is to say, although the rear position may not work well for you personally, this may be a question of user preference with no generally superior solution.