One of the things we've been doing semi-successfully is adding more rigor to the tests, and retaining historical data, so we can better compare "improvements" going forward. Right now I see too much latency compared to the original (2016) ath9k effort, and don't have any good data on multi-station performance with the fixes we've landed to date. I think the
tx_queue_data2_burst=2.0
(and 3) AP changes need to be tested on more hw in particular, which will improve throughput from the AP in contended scenarios. Two patches starting at: Reducing multiplexing latencies still further in wifi - #10 by amteza have not made it into rc6, but are just scripts....
So my hope would be for all of us, to somehow, going forward, to not be "inclined" to think things have got worse or better, but to actually know. 