Asus zenwifi or Asus routers with AI Mesh?

[neonplanet40]

Hi folks, looking to complete my home WiFi setup and ensure there are decent speeds.

I currently have:

Asus RT ac68u
Asus RT ac86u

Both are used as individual wireless access points connected via ethernet to my home network and internet (talk talk router with wireless turned of, used just to provide internet to wired network). (Both Asus routers offer separate 2.4 and 5ghz channels).

My main wireless is the 86u. The 68u is in the front room close to door to ensure a strong signal for my Ring Pro doorbell.

However, to simplify things, I want to make use of Asus ai mesh. What I need to know is, would I be better:

Selling both routers and getting the Asus Zenwifi ax xt8 pair and using these for my house and doorbell. Both would be connected via ethernet to the home network.

Or buying something like the Asus rt88u and adding it to the 68u, 86u and connecting them all to the network via a wired Ethernet connection and then connecting via ai mesh?

Just wondering what would provide the best speeds for me? I do watch 4k over my wireless in my tablet via Plex. I am able to do this fine with the 86u as it seems quite fast. I can't do it with the 68u as it isn't quick enough to provide the bandwidth. I'm just unsure how using different routers will affect speeds etc. I.e. will they be forced to operate at the slowest router in the bunch's speeds etc.

Thank you

[neonplanet40]

Just a bump for anyone with knowledge who can help

[neonplanet40]

So, I have sold my ac86u (might sell my DSL68u as well). I have bought 2x RTAX86U and will use them in AiMesh mode. That should work well as reviews are good and Merlin will support it.