Just to have fun (and not let this subject die that fast
), power line does a good job!
Considering apartments / dense urban environments:
1.) In such environment you will be sooner or later interference limited on 5GHz Wifi as well (you might already be today in most European cities).
Specially now that most routers/boxes have 5Ghz and DFS limitations.
So basically today what you get between 4x4 AP and 3x3 client (like macbook) is probably the best you ever get
and in the future you might even get less. (until the new 6GHz Wifi comes in 2 years or so).
So "designing you network for the future" is just not possible with Wifi in dense environment and I would say do ethernet cabling if you really want
1G+ (10G?) throughout your home/apartment guaranteed.
2.) previous PLC devices were not as good as today. Even the 100Mbps class devices have SW/FW improvements which increased
the performance/reliability dramatically till today! Whatever you tesed with PLC 3 years ago does not apply anymore.
3.) What ever you get with PLC you have it, and its not taking your Wifi bandwidth away.
4.) Always plug PLC on the power plug directly. Not on a multi plug extension line. Best are PLC passthrough plugs for that.
So all in all, seeing the financial effort (low) to use PLC, I would give it a try with NEW products (like the Mtik ones) if you want your throughput
guaranteed!
Now if you life in a Castel in Nova Scottland (or someplace like that), then the situation is different. But that is not the starting point of this discussion.
(and then get you a 8x8 AP).
Personal opinion, don't shoot the messenger...