I've recently put 4 power line adapters in my house. The house was built in 2005 and doesn't have any Ethernet run through it. I'm using the cable modem/AC router on the main level which was distributing WiFi to the finished basement and to the second floor. While the AC WiFi could get a very high max throughput which matched or exceeded my internet's 170mbits per second, I found it to be less than reliable in practice, especially in my master suite which is located above the garage since the router has to deal with insulated walls. Once you've got a couple of consoles, a desktop computer, a Macbook, a couple of tablets, phones and a couple of apple TV's all trying to use the Wifi at once, it failed pretty spectacularly. (I have a big family)
I installed 4 TP-Link "1200Mbit" power line adapters in the house. One is at the router, of course, one behind the main TV with consoles and apple TV, one behind the upstairs TV with a console and apple TV (Ethernet switches used). The remaining one is attached to the desktop PC.
These are not the newest hotness "2000mbit" versions but they are, all the same, AV2 with MIMO and repeating.
I have found that they do not suffer from interference. They provide the same level of performance whether every heavy appliance in the house is running or if nothing is running. So what level of performance is that?
-About 150mbits everywhere except the master suite which is 127mbits.
Yes, that's less than the max that the WiFi can put through but it's utterly reliable. Pings are low and packet loss is 0. It seems to be a ring topology because streaming an HD movie (23mbits) will reduce the bandwidth to all other units by that amount. With both TVs in use doing HD streaming, the desktop still has about 100mbits available, again, with low ping and 0 lost packets. Would you take 100mbit Ethernet over 170mbit WiFi? I would and I am.
Stuttering of streams and other similar problems are a thing of the past in this household.
Naturally, wifi is also much better now since the only thing on it are things like tablets and phones. The big data hogs are moved to the wired solution.
I suppose it might be a good idea to get the newer 2000mbit hotness but these were on sale at Best Buy (Canada) for $60cdn/pair. The 2000mbit ones were $100 and use the same AV2 MIMO standard, just at a higher data rate. Worth 167% the cost? Since these work so well, I say no.
I also have some MOCA adapters which work even better on their own but they're limited to where coax is run and, sadly, no longer function in my house after the installation of a whole home DVR which uses MOCA and blocks my adapters. Power line has no such limitation and will work anywhere you have an outlet.