All of these features are well-designed and easy to manage via the Deco app. Most importantly, they worked as intended in my trial. I wasn't able to do a thorough test of its antivirus' effectiveness, but when I tried accessing known bad websites, I did, instead, get a warning that the sites are blocked. The feature, which doesn't incur extra cost, is powered by Trend Micro, so generally it's safe to say that it's as effective as Trend Micro's antivirus software.
The M5 is not the first Wi-Fi system with built-in protection; the-- which costs $299 for a set of two units -- also has a similar feature powered by AVG.
No back-haul band
Unlike the Ally, the M5 doesn't have a dedicated band for backhaul, the job of connecting its units together wirelessly. For this reason, in my testing, the system clearly suffered from signal loss, meaning devices connected to the satellite units have a net connection speed more than 50 percent slower than those connected directly to the main router units.
The good news is that the M5 allows you to link the units together using network cables, which will eliminate signal loss completely. TP-Link says you can connect up to 10 M5 units together and can even connect some of them via network cables and the rest wirelessly.
Great range, reliable performance
I tested the M5 over a week and it delivered reliable Wi-Fi with similar performance to other dual-band systems like the Google Wifi or the Eero. And even with the signal loss, its Wi-Fi speed was still faster than most residential broadband connections.
It has excellent Wi-Fi coverage, too. I was able make it cover some 4,000 square feet of residential setting with a sustained Wi-Fi speed of more than 100Mbps. Like all systems, you can adjust the Wi-Fi coverage by placing the units at different distances from one another. However, keep in mind that large Wi-Fi coverage always means slower Wi-Fi speed, so pick a balance that you're comfortable with.
Should I get it?
If you already have a Wi-Fi system, the M5 doesn't have enough to qualify as an upgrade, unless you really want the antivirus feature. However, if you're using a single router and having problems getting Wi-Fi everywhere, you should definitely consider replacing it with the M5. TP-Link told me that comes June, it will update the M5 with the access point mode, allowing it to work seamlessly with an existing router. That said, if you're using a modem/combo device, maybe wait a month or two before getting your own. And by then, chances are there will be even more options on the market.