I was about to write about the 5 GHz band and how much better it is than the 2.4 GHz band. But I find that my Wi-Fi books are seriously out-of-date. So I have ordered a new book, but in the meantime, I will try to provide an overview of the major points.

First, the 5 GHz Wi-Fi band provides wider channels. This means that individual devices can communicate at higher speeds. Also, 5 GHz provides more channels. I'd have to check the latest spec, but 5 GHz subchannels number in the triple digits and twenty-four of them are non-overlapping, depending on the channel bandwidth selected by your device. So this means that more devices can share the 5 GHz band without interference.

However, as with 2.4 GHz, your router will typically only have one 5 GHz radio, so your local Wi-Fi network will be limited to that one channel. That should not be a problem in your detached home in the burbs. But, back to the 30-unit apartment example: those 30 individual routers could spread themselves out over many different channels, so using the 5 GHz band might reduce the number of devices interfering with each other on each channel. And that's good.

The bad news is that those 30 routers will not all be able to get dedicated channels, so we are back to the same sharing situation we had on the 2.4 GHz band, at least on some channels.

The other bad news is that, due to the physics of radio waves, 5 GHz signals do not penetrate space and barriers as well as 2.4 GHz. Thus, an individual 5 GHz router will generally provide less coverage. In some cases, in a larger building for example, additional 5 GHz access points might be required to reach every device.