I have a MikroTik hAP ac² running IPQ4018(16/128MB), a few xiaomi R4A Gigabit running MT7621AT(16/128MB) and an Asus RT-AC2400(same as RT-AC85P, 128/256MB, MT7621AT).
ISP is FTTH 300/100, upgradeable to 600/300, pppoe.
Since wifi on mikrotik routeros was crap, I temporarily put asus with openwrt as the main router until I flashed OpenWRT on mikrotik. It was mainly to get 802.11r and band steering functionality. I also run a wireguard client on the asus now.
Do you think it would be better to put MikroTik back as the main router, or does the MT software support outweigh the physical 4-core CPU in the mikrotik? MT7621 is a 2c 4t cpu.
ipq40xx tops out around 300 MBit/s (considerably less with sqm). Yes, ipq40xx is faster (CPU wise) than mt7621, but mt7621 has an extremely streamlined networking network design/ drivers - it can gain/ surpass ipq40xx in that regard for the 'simple' case, but that falls apart for more complex setups.
applies to your situation, meaning you should skip both of these options (in terms of mere APs, ipq40xx slightly tops mt7621a+mt7603e+mt7612 and might be more on par with mt7621a+mt7615n+mt7615n, while mt7621a+mt7905+mt7915 would surpass it again)…