@sturmstar, I'd be more interested to know the throughput on the different 2.4GHz band routers at the same distance on their optimum control channel (1, 6, or 11). With all other routers
off during the comparison.
Having installed my fair share of RT-N66U's, RT-AC66U's, RT-AC56U's, RT-AC68U's, RT-AC3100's, RT-AC86U's and lately RT-AX88U's, over the last few years, I have only seen increases in real-world performance. Otherwise, I would not have been able to sell the newer routers.
I don't care about arbitrary things like signal strength or apps that measure such things either. Because I've found that that is not a good way to predict what will be a solid WiFi implementation or not.
Each router I've set up and installed has its own 2.4GHz and 5GHz band 'optimal' channel, depending on the environment it was placed in. When set to that control channel the newest routers have always performed better than what they replaced (and it could have been a different control channel or not on the older router).
I don't sell specs and dBm increases to customers. I sell them a router that makes their networks faster and has more coverage, overall. Regardless of what the cute but effectively useless 'apps' may suggest.