"kpeex" posted this in the SE ORDER THREAD but I'm having the exact same issue with my SE and I wanted to make a new thread about this problem.
I actually had to return my SE back to Verizon because my Bluetooth calls reception quality was terrible. Playing music or YouTube videos through the Bluetooth was excellent but when it came to phone calls, the sound was constantly cutting in and out and sounded "scratchy" and distorted.
Never had this issue with my previous 6S or my work-issued Android phone. Tried my SE in a different vehicle and got the same results. I've unpaired and repaired and I even restored my SE and set up up as a new device but nothing has worked.
I'm hoping that my SE was a "lemon" and this is not a known issue for this model. When I receive the new replacement, I'm going to hold off updating to 9.3.1 and see if it might be a software related issue.
Are any of you guys experiencing Bluetooth call reception issues with your SE?