When we're designing a system, the most important aspect is to ensure that the broadband is well distributed throughout the property both by cable and WiFi.  

One of the major failings of Smart devices is when they rely too much on the WiFi network.  Sky Q is a prime example of this.  Its a brilliant but flawed system because by default it uses the WiFi network when in most cases it works far better wired straight back to the router, usually via a network switch.

The fact is, theres usually so much traffic on the WiFi network that some devices, especially those relying on streaming large amounts of data, simply cant find enough space to operate properly causing dropouts and buffering.

Wherever possible a wired system will always be better, so the more fixed devices, PC,s Apple TV, Sky Q, etc that can be cabled, the more space available for the WiFi only devices. This signal can then be spread to all corners of the house via carefully balanced WAPs (wireless access points) which re-transmit the signal to maintain speed.  Often several WAPs are needed in a large property.

However, don't confuse WiFi signal strength with broadband speed.  You definitely need good signal strength throughout your home but without a good broadband connection its pointless.  Often (too often in our experience) a really good balanced network will be badly let down by a poor or intermittent broadband connection so its vital that your provider is made aware of your needs and equally important to monitor it on a regular basis to ensure that the speeds remain up to spec.  Sometimes the broadband can exhibit good speeds but with brief dropouts.  These dropouts can cause havoc with some devices.

So, no matter how good the network, the final speed will be dependent on the broadband connection and main router. -  Win this battle and you're there!