@Jem8239 

If all you need is WiFi coverage improvement, Deco can be good solution.

You can configure Deco in Access Point mode, so that it will provide WiFi signal, leaving your router to manage network like it does now. In Access Point mode, you can connect Deco unit to any Ethernet cable in your household and it'll use it for wired backhaul. This is ideal setup for any WiFi mesh, and Deco utilizes it fully.

Deco units have 2 Ethernet ports. If you already have something connected to Ethernet cable where you want to add Deco, you can plug Ethernet cable to one of two ports of Deco unit and that "something" to second port. 

Deco mesh is expandable, you can buy additional units and add them to your home network, seamlessly.

If you are OK with WiFi 5, look for Deco models M4 and M5. 

If you really, really need WiFi 6, then buy Deco X20 or X60.

Three caveats specific to Deco:

1. There is Deco model E4, which looks exactly like M4, but E4 has 100Mbps Ethernet ports. M4/M5/X20/X60 all have gigabit Ethernet ports. If you are buying from places like eBay, they might sell you E4 claiming it is M4. 

2. Deco mesh does not work well with D-Link Ethernet switches. If your home network runs on D-Link switches, you'll either need to replace them or look for a different WiFi mesh.

3. You will need smartphone to configure and manage Deco mesh. They have app for Android and iPhone. There is no Web interface for managing Deco.

@Alexandre. Thanks so much!