I place a very high priority on reception / signal quality so I decided to run some tests on two identical 128gb iPhone 7's to see which is better in my environment (planning to return whichever one is worse). One Verizon / qualcomm model purchased from Apple store (model a1660), and another purchased from an ATT store with the intel modem (a1778). The phones are set up identically as new, and both have 10.0.2. Reset network settings on both phones and used the speed test app for LTE speed tests. All tests run on AT&T's network. I only kept tests where the speed test app connected to the same server/location. I also did a field test prior to each run. Averages below are based on 10 total runs.
Bottom line is I found a significant difference - average downloads of 22 vs 13 mbps down and 3 vs 1 mbps upload speed (qualcomm was the winner). Also lots of variability for the intel modem during the tests, where the qualcomm modem was more steady through each speed test run. And did a bunch of simultaneous page loads of web pages (on LTE). There was little difference in page load speeds.....maybe a very slight advantage to qualcomm. Lastly, after running all these tests I compared battery life. I also set the phones next to each other and did a 2 hour call between them to see if an LTE call used more battery on one of the models. I was careful to make sure the phones were set and charged identically, and ran the same amount of tests / screen brightness on each phone. Battery life at the end of the tests was as follows: Qualcomm - 75% remaining. Intel - 61% remaining. I did not calibrate both batteries beforehand FWIW.
Attached is a txt file with my test data. Hope this is useful to people. I fully realize this is just one data point with only two phones, and I understand there's a need for a more scientific and comprehensive test with many more phones and locations to know for sure. But I thought I'd share what I found in case anyone finds it useful since I rarely if ever contribute to these forums, but frequently get useful info from others' posts.