5GHz works well as long as your access point is in the same room.
In real life one of the drivers behind having so many wireless devices in the first place is avoiding the effort and cost of laying cables everywhere, 5GHz often doesn't solve that problem well.
For now I'm using powerline devices to connect rooms with their own set of problems, nothing beats having a well thought through wiring in the house though.
My house is over 100 years old with fairly thick walls, knob and tube wiring, and a lot of neighboring 2.4Ghz access points. I ended up going under the house and running cat6, which was no small feat considering how tight the crawlspace is.
Of course, the cat6 cable I used subsequently got recalled, and so the manufacturer had to pay for a contractor to rerun it. They said that it was the type of job they wouldn't have even quoted for any price originally because it was so gnarly.
I have 2.4Ghz and 5Ghz from two APs on either end of the house. I turned off support for pre-n speeds on the 2.4Ghz to hopefully save some bandwidth on the beacon frames. I have Ethernet over Power to my garage, where I have a third AP for our inlaw unit.
The Ethernet over Power seems to be pretty good, but I had to find the right brand of equipment for it to not be flaky. WiFi still sucks, but my desktop and TV are hardwired, and it's good enough for mobile devices. I can go for about a week without losing my work VPN connection, through wifi through Ethernet over Power to PDSL.
If you care about interference ethernet over power is awful. It basically turns all of your electrical wires into a giant antenna and broadcasts that as broadband noise over multiple miles.
The only reason the things aren't outright banned is the frequencies tend to be sub 100mhz so it only has a significant impact on HF. Still, nasty things and many have been found over the legal noise limits.
If you can I recommend point to point 2.4ghz wifi links. Since wifi is regulated by ERP they have a high gain antenna that usually punches through things better than an omni AP. I've done them through multiple walls from 300-400ft away.
That certainly sounds reasonable. I've poked around with an SDR though, and the only egregiously noisy thing I've seen is the one 100Mbps Ethernet link from the DSL modem to the router.
Before I ran cat6, I indeed used WDS wifi. It wasn't reliable, though, and the particular hardware I had suffered from a bottleneck somewhere that seemed to limit throughout to 6Mbps or so. I could have spent another $500 on less crappy equipment and maybe made it work, but moving to wires everywhere I could was highly effective.
In apartment buildings, there’s no advantage in a wireless protocol that penetrates walls—quite the opposite. I don’t want my neighbour’s router and mine constantly shouting over each-other. I want the signal to end at the wall.
Agreed, this would be ideal. Most people don't understand that literally every access point on a given channel is part of the same broadcast domain even if they're totally separate networks. Every AP that yours can see on the same channel slows down the network for all of them, because wifi is half-duplex. Everyone needs to shut up for a second while one host on the channel transmits.
I see more than 20 networks in the building I'm in, so that is already happening.
Most people I know don't have cables going to different rooms, there's a router where the signal comes in and wifi from there. Often there's not even the choice which room or part of the room that is.
Unless your building is relatively new and someone thought about setting up the cables, it can be very expensive to do so later.
To lay a cat6 cable and have it snake over the ceiling in a cable gutter? The cable I grant you isn't dirt cheap but it's by far the most expensive part of that arrangement.
I live in a small house in a big city and 5ghz is the only usable spectrum. The connection is solid through walls and there is a minimum of interference from neighbors -- I can only see my immediate neighbor's wifi, whereas 2.4ghz I get broadcasts from the entire block and can't even stream Netflix
In fact the lack of range works so well that I can use almost the entire spectrum for various networks and not feel guilty
In real life one of the drivers behind having so many wireless devices in the first place is avoiding the effort and cost of laying cables everywhere, 5GHz often doesn't solve that problem well.
For now I'm using powerline devices to connect rooms with their own set of problems, nothing beats having a well thought through wiring in the house though.