This is from 2018, with an update from 2019. It primarily focuses on the Wooting one, which is "sold out forever." The key touted advantage of the Wooting one

This is from 2018, with an update from 2019. It primarily focuses on the Wooting one, which is "sold out forever." The key touted advantage of the Wooting one keyboard seems to be optical switches with an adjustable actuation point. It also uses a multiplexer for each row of keys, which is somehow faster than a scan matrix. I don't see an actual test result for the keyboard that includes all of the latency factors discussed. The closest is a link to a tweet by Sunjun Kim. Unlike Dan Luu's measurements, which actually pressed a key, Sunjun triggered the optical switch using an LED, resulting in latency of 4.2 to 9.6 ms, depending on the firmware. According to this post, key travel can add up to 10 ms, which the adjustable actuation is supposed to minimize. That would put the total latency at 10 to 15 ms, which is around what Dan Luu measured for Apple's Magic Keyboard.