how will adblock performance on this compare to x36 dynalink ?this has "512mb" only.
Good, unless you use really huge block lists, but one of the reasons why the WRX have 1gb RAM is because the ATH driver/sw requires a lot more RAM than the MT.
My WRX have approx 570MB free when it's up and running, as AP.
personally I use adguard home, which uses almost 250-300Mb on rpi4, with this block list. so anyone of these two will do?
Depends what else you run on your router, mine are really stripped down, since they're APs.
The AX4200 is a PTA to flash thought, requires serial.
ISP speed is just 50Mbps so SQM isn't a big load on the CPU I think. so need to compare adblock performance only.