Update after a few months of daily use: The WD My Net AC1300 has performed very well for us. We have noticed no outages that were caused by the router and I would say that the latest firmware is very stable. If you have problems with your router, make sure to check for a firmware update. (If you have never done this before: Enter IP address from the manual into the web browser and use the standard login, found on the bottom of the router itself. Navigate to "Settings" and find the button to check for firmware upgrade.)
Speed-wise, the router has not really been pushed to its limit. Our older laptops cannot take advantage of Wi-Fi ac and only one smartphone actually uses it. So the speed of file transfers is hindered by the hardware using the network, not the network itself. However, close to the router my laptop can reach almost the speed of our internet connection. For most users that is all they should really hope to be able to do.
Would I recommend the WD My Net AC1300? I guess it really depends on where you want to use it. If you live in a large house or you want to receive a strong Wi-Fi signal in the garden or your garage, there might certainly be better routers for you. Ones with directional antennas can usually cover large spaces better than routers with in-built antennas. Directional antennas can also be upgraded if necessary, which is often cheaper than setting up a Wi-Fi repeater or an access point. If you live in a small house or in an apartment and don't want the Wi-Fi signal to extend too far beyond, the WD My Net AC1300 is certainly a great solution. It is still one of the less expensive routers with Wi-Fi ac. It also comes with two USB ports, which allows you to connect a printer or a hard drive and share it through the network.
Original Review from September 2013:
This was the cheapest WiFi AC router with two USB ports that I could find. It works well in my setup, because it only has to cover an apartment. This router does not have the range of some other WiFi AC routers. Get the one from Asus if you have a big house or you want to cover a large area. I did not want my network to extend too much outside of our apartment, so this is ideal for me.
Setup was really easy. My laptop (running Vista) actually set up most things automatically when I connected it to the router. Afterwards, I used the browser to connect to the router and changed some settings.
I would recommend upgrading the firmware of the router right away. My unit shipped with older firmware and since upgrading I noticed slightly better performance. You can also set up a guest network, change channels etc.
A nice surprise was, how easy it was to connect the printer and an external hard drive. I connected the printer (brother all-in-one) through an ethernet connection and it was automatically recognized and I was able to print from my laptop right away. I did have all the brother software pre-installed on the laptop. I also got the brother app on my tablet and can easily print from my tablet over the network.
The hard drive just needs to be plugged into the USB port and the router lets you set up a password protection, in case you do not want everyone on the network to have access to the data saved on the hard drive. I connected a WD 500GB 2.5" hard drive and it worked without any problems. Connection speed seemed to be okay. Depending on the location, it took me usually about 1 minute to transfer a 1GB file from the hard drive to my laptop (my laptop is old and cannot take advantage of the WiFi's speed). Newer laptops, and especially ones with WiFi AC should see dramatically increased speeds.
I got a WiFi AC router to future proof our network. We do not actually have any WiFi AC devices yet, so I deactivated the WiFi AC through the router settings. Now it only transmits a WiFi g signal on the 5Ghz band.