The above mentioned reddit thread is one that I started...and I wanted to post my updates in here since this thread is what drove me to do all of the testing. Below are a few of the points I have learned since last night (all testing done in the same place at the same time with SIM cards from the same phone plan, all speed tests completed using T-Mobile Orlando server)...
Download Speed: Qualcomm still seems to VERY SLIGHTLY lead the pack in both low and high signal areas. The speeds come on faster, and don't fluctuate quite as much as the Intel while testing. But then again, is the difference between 152mb and 155mb worth searching for a phone over?
Upload Speed: Every single Qualcomm test results in a very elevated upload speed in the first second of testing, followed by a sharp drop down to sub 10mb speeds for the next second or two, then slowly ramping back up to full speed. Intel starts off at lower speeds than the Qualcomm, but does not experience the sharp drop in speeds after the first second. Both devices usually end up close in the end, with the Intel slightly edging out the Qualcomm. Same as before though, are we looking to split hairs with 25mb vs 27mb upload speeds?
Ping: Literally no difference between devices. Out of approx 100 speed tests run all over CFL in the last couple of days in a mix of low and high signal areas, averaging out ping times results in a 1ms difference favoring the Qualcomm modem. If you can tell a 1ms difference over 100 tests, you are better than I am
Battery: Still no perceivable difference between either unit. Battery draw appears to be the same, but without having a scientific way of making sure both phones are charged to the exact same level and performing the exact same functions with the exact same signal level, any differences here are going to be guesstimates more than anything.
Reception: This is a funny one, as my Intel phone consistently shows higher signal than my Qualcomm phone, except for in strong signal areas where they both show full signal. The Intel phone tends to drop from 2 bars down to 0 faster than the Qualcomm, where the Qualcomm does like to show you 1 bar in between. Driving through known dead areas resulted in both phones losing signal at the same location, and recovering within seconds of each other every time with a very slight edge to the Qualcomm.
Voice Quality: Intel has a slightly better sound quality, but almost imperceivable on the device side. Callers have noted a warmer sounding voice with the Intel phone, and slightly less background noise. I have completed multiple blind tests with people that would not normally be able to tell much difference, and in all cases the Intel phone was able to be determined. With that said, I was told that differences were minor, and had I not pointed out that I was using different phones it wouldn't have been as noticeable.
EVS: *SHRUG* T-Mobile is using EVS-WB 13.2kbps CODEC, which means barely any performance and sound quality gains above and beyond AMR-WB 13.2 that is used in all other HD Voice devices. EVS-WB is limited to 8khz bandwidth while AMR-WB is limited to 7khz. Both Intel and Qualcomm phones cut off at 7.6khz when using T-Mobile's EVS network, so any differences in sound quality as a result of EVS are going to be slight. I did note that weak signal areas that resulted in garbled audio and dropped calls with my QC 7 did not experience such issues with either the Intel X or Qualcomm X, but unsure whether this is EVS efficiencies or modem/antenna performance differences.
Hopefully this helps, but it is my opinion that searching for a Qualcomm phone just to have CDMA capabilities when you will never use it is silly this year. Until someone can perform more scientific testing, I think this is about as extensive as we are going to get. For me, I will be sticking with the Qualcomm phone simply because I do tend to swap back and forth between T-Mobile and Verizon, but otherwise I would keep the Intel simply for the new Field Test mode that allows me to see signal and carrier aggregation status.
