the speedtest in the video is limited by the tester's broadband speed, wonder what its max performance is. hope SNB can conduct a proper test... but I doubt it..
In my limited experience with homeplug stuff, you are generally looking at 25% or so of "rated speed" for maximum usable speed and that is on the same circuit without much feeding back in to the electrical wiring. IE ideal conditions.
PHY rate typically seems to be between 40-60% of max PHY rate listed for the product under ideal conditions and you are generally going to get around 50% yield on PHY rate once ECC, rebroadcasts, etc are factored in.
So a 1800Mbps product under ideal conditions and if the firmware, adapter, etc are good, you are probably looking at around 450Mbps at best. Which is rather good, but this is under ideal conditions, which isn't often what you'll be under, since you generally aren't using a homeplug on the same circuit, because that is often just across the room or maybe one room over.
So depending on the installation and everything else, figure more in the 150-300Mbps range...which is still very good.
Its nothing like 1000Mbps full duplex of gigabit ethernet though. Or for that matter, not nearly as fast as a good 1300Mbps bridge 802.11ac connection. I've seen plenty of guys at decent distances bridge AC1750 routers (in 5GHz 3:3 80MHz mode of course) get usable numbers of over 300Mbps. Heck, Line of sight and 20ft away I can get over 440Mbps between my Intel 7260ac and my AC1750 router, and that is only 2:2, not 3:3. Stick a wall in the way and 30ft and I can still get over 300Mbps. That might not be the kind of situation you'd have for powerline, the wireless situation is often worse, which is why someone is opting for powerline.
However, powerline still really remains the networking choice of last resort. It is getting better and by leaps and bounds the last couple of years, but it is still the 3rd rate networking choice (at least with the newest PL adapters, probably better than MoCA, at least 1.1 and maybe even 2.0 (which pretty much can't be found) under some select circumstances with this upcoming crop of 1800Mbps PL adapters).