First, don't feel compelled to
have to go AX. Except for up to 2x more throughput in 2.4Ghz for AX clients only, all other "features" are basically vaporware, for at least the next year, potentially longer.
Second, even though you've got fiber, at 200Mb/s aggregate, you're probably going to want
SQM QoS to keep bufferbloat at bay. An AX58U with Merlin should do decently enough in that department, and its 2x2 radios should be good enough for most clients, especially if your residence is on the smaller side. I'd test it at at
DSLReports Speedtestest for download and upload, with no QoS enabled, just to collect actual speeds. Then enable fq_codel in Merlin QoS settings with those download and upload values. If bloat is a "B" or worse, test several more times after making sure your fiber gateway/ONT and all other upstream items are in-check. If it's still poor, exchange for a Netgear R7800, flash OpenWRT + SQM packages, configure with CAKE as your qdisc and you should get an A or A+ no problem. Or just do an R7800 straight away. Not giving up much at all; in fact you gain 4x4 radios for better receive sensitivity and real-world effective throughput over distance, for all AC and AX clients. But if you're leaning towards Merlin and Asus, give that a shot first. Not a
ton of difference between the two platforms.
Or, if you don't want to monkey with any of the above and have something that "just works" out of the box, simply buy an Eero Pro tri-band base unit and toggle SQM to "on" in the Eero Labs section of the phone app. Done.
