There’s almost no comparison between the two. But just depends what you want it to do. If you want things like bandwidth monitoring the network lacks that as an example.
Most AX all-in-ones, include these two, could probably stand to have several more rounds of QA/QC applied to their firmware before they would stand a chance at being what most would deem long-term "stable".
If you simply had to stick with an AX product for whatever reason, I would opt for an AX88U running Merlin; at least that way it's just about as bug-fixed as one could hope for.