JustAsking wrote

I have a reasonably large house over 3 levels and have recently acquired 3 x Deco X50 and am very pleased with the results, so much so that I am considering changing my modem. I can get an AX1800 X20 at a very good price but am I better off waiting, as I am in no hurry and get an AX3000 X50?

  @JustAsking 

Hi,

Are you talking about the Deco X20-4G and Deco X50-4G with built-in 3G/4G modem?

  @woozle Thanks for the reply. No, the AX1800 X20 DSL Modem/Router of the AX3000 X50 DSL Modem/Router.

  @JustAsking 

If you intend to use the Wi-Fi part of the Deco with the built-in DSL modem, then it would certainly make sense to get the Deco X50-DSL, as its Wi-Fi specs would match those of the other three Deco X50.
 

  @woozle Thanks, is there reasoning behind the recommendation as from what I can find out, the only difference between the 2 units is the X50 DSL has twice the 5GHz speed but the same at 2.4GHz, which it what I will use as some of my smart home items can't run on 5GHz.

  @JustAsking 

The reasoning behind getting the Deco X50-DSL would have been the same as the reasoning behind getting the other three Deco X50.

However, now that you mention you only need the Wi-Fi for connecting some smart home devices that use 2.4 GHz Wi-Fi, the 5 GHz Wi-Fi capabilities of the Deco certainly don't matter. Most probably those 2.4 GHz-only smart home devices can't even utilize the Wi-Fi 6 (802.11ax) capabilities of the Deco X20-DSL.