I bought two iPhones last year, a Sprint iPhone 7 and an AT&T iPhone 7 Plus. The Sprint's Bluetooth Audio had no issues. The AT&T 7+ skips like a scratched CD on any and every Bluetooth device I own. So far I've tried:
-Reproducing the skipping (successfully) on Altec Lansing, FitAcoustics, Beats Solo 3 Wireless, Sony ZS-RS60BT stereo, 2 Subaru Forresters, a Cadillac SRX, 2 Mpow Cheetahs headsets, 2 Bluedio headsets, a portable JBL speaker, AirPods, Here One earbuds...I could go on.
-Resetting Network Settings (to clear out all bluetooth other devices) and pairing to online one device
-Not logging into iCloud (to prevent AirPods from syncing their Bluetooth profile)
-Wiping and restoring to the same firmware
-Not restoring from local backup (and setting the device up as new)
-Not restoring from iCloud backup (and setting the device up as new)
-Five different firmwares — 10.1, 10.1.1, 10.2, 10.2.1, 10.3 beta
They've replaced my 7+ three times now and I still have the issue. I've probably spent 5+ hours on the phone with AppleCare by now re-explaining repeatedly, uploading error logs, reading off serial numbers, etc. If there were a software fix they would've found it by now.
The only question is when will Apple start recalling these phones.