@RobHe 

Hey

Being honest, coverage isnt something you can fix by changing the model of AP, its generally just down to adding more APs.    

WIthout going into too much detail here.. the distance a WiFi signal will cover is determined by a value called EIRP (effective isotropic radiated power), which is a numerical value for the 'power' of an access point.    This can be increased by more transmitter power or a bigger antenna in the device, however its a case of diminishing returns as you increase this.   Double the EIRP doesnt mean double the distance, in fact it can be sub 10% at best.

As nearly all decos are roughly the same power and antenna size and therefore EIRP is roughly the same, all deco nodes are as close to the maximum levels allowed by law for indoor use. 

In short.. its unlikely to make any real change to your coverage, you will need to add more deco nodes if coverage is your aim. 

What a newer version of the Deco (x20 for example) would offer you is increased speed to anything connected with WiFi6 capabilities, WiFi6 is becoming more common.

Sorry that may not be the answer you where looking for!  Welcome to the world of Wireless!!  If you have any queries just ask below