I provided this to the techs weeks ago, but it seems like there was no headway. So here are the results of my trials for everyone to read:
I work in an environment where I have access to soundproof rooms. The walls are steel with padding and are about 6" thick (solid). These are "dead spots" for wireless in my building, which I surveyed and had to plan around because of the walls. I also work with deploying a lot of iOS devices, so most of my colleagues have an iPhone.
Testing environment:
I tested the area with an OptiView XG using AirMagnet Spectrum XT software. This device and software is used to measure the amount of Radio Frequency (RF) radiation in a given area to troubleshoot issues with wireless, and to help design wireless networks for large corporations. This helped me to ensure that there were no stray 2.4GHz interferers while testing, meaning that the only devices emitting 2.4GHz band RF were the "Devices" listed below (Beats Pill, Plantronics Backbeats, Braven BRV-1) and the phones.
Additionally, I tested the cars listed below in several environments with and without interferers nearby. These were less controlled, however mirrored the exact same results.
Stuttering/Skipping:
To show an example of the skipping sound that I am referring to, please take a look at this video: https://www.youtube.com/watch?v=kGHFDRVA958
Bluetooth devices tested:
- Cars: 2013 Ford Focus, 2011 Toyota Venza, 2007 BMW 335i, 2006 VW Jetta
- Devices: Beats Pill, Plantronics Backbeats, Braven BRV-1
iPhones tested:
- iPhone 6s - No problems
- iPhone 6s Plus - No problems
- iPhone 7 Plus (AT&T, A1784) - Stuttering
- iPhone 7 Plus (AT&T, A1784) - Stuttering
- iPhone 7 Plus (AT&T, A1784) - Stuttering
- iPhone 7 Plus (T-Mobile, A1784) - Stuttering
- iPhone 7 Plus (Sprint, A1661) - No problems
- iPhone 7 (Verizon, A1660) - No problems
- iPhone 7 Plus (Verizon, A1661) - No problems
- iPhone 7 Plus (Verizon, A1661) - No problems
- There were two other GSM iPhone 7 Pluses that I trialed, but I don't have the model numbers in front of me to list to provide exact details. Both had issues.
As you can see, the issues are localized to the GSM models using the new Intel modems. This further solidifies the belief that there is an existing hardware issue and not a problem with software, interference, or other manufacturer's devices. I'm not sure what else I can do to troubleshoot with the Apple reps, but after spending upwards of $5000 with Apple in 2016, I can't help but to feel neglected.