Be aware that the hAP ac² numbers are RouterOS 6 numbers and you’ll need to deduct 25% or so when doing comparisons with the two other RouterOS 7 (out of factory) devices. Look at the hEX RB750Gr3 as an example, before the hEX refresh was announced the old hEX boasted values of 385 Mbps in that special column https://web.archive.org/web/20241004221058/https://mikrotik.com/product/RB750Gr3#fndtn-testresults because those were RouterOS 6 test numbers. And now MikroTik has significantly reduced those numbers, by using the real applicable numbers from RouterOS 7 (to compare with the hEX refresh).
With my hAP ac² if you disable fasttrack, by using the defconf firewall with IPv6 prior to 7.18, or by using the defconf firewall for IPv4 but with the fasttrack rule disabled, I could achieve speedtest.net result around the 7xx Mbps range with RouterOS 7 (with PPPoE WAN). Which means it’s inline with a 25% reduction compared to the published value for RouterOS 6. Which means the hAP ac² when running RouterOS 7 without fasttrack should be slower than the hAP ax² with its 913Mbps published ROS7 number. With the RAM and storage restriction, the hAP ac² should no longer be purchased new. If you can find it cheap on the second-hand market then you can use it as a wired-router/managed switch (turning on WiFi is risky because you can expect any new release of RouterOS 7 to completely fill the flash storage any time).