Like Apple’s current-generation AirPort Extreme and Time Capsule routers, the Buffalo WZR-D1800H supports 3x3 MIMO technology, meaning it can benefit from using multiple antennas simultaneously. This gives an overall performance boost, and because of that can help with range, too. It also means that the speed-testing process is a different beast because, as you’ll see in the chart below, the router performs better when transferring multiple files simultaneously (sometimes quite a bit better!). Of course, your Mac has to support this, as well.
All current iMacs and MacBook Pros support 3x3, and the MacBook Air supports 2x2. For 802.11n, think “150 Mbps per supported stream,” which means iMacs and MacBook Pros can support 450 Mbps wireless link rates over 802.11n and MacBook Airs support 300 Mbps link rates.
As you can see in the chart, link rates don’t translate directly to transfer rates, but they do increase together. For my tests I used a 2011 iMac for the 802.11n portion, and to test 802.11ac I used Buffalo’s new AirStation WLI-H4-D1300 Wireless Bridge. This device acts as a wireless client that has a 4-port Gigabit Ethernet Switch. It gets its signal wirelessly — and at 802.11ac speeds — from the router, and then allows your Ethernet-connected devices to transmit over that bridge. A great idea because, of course, there aren’t any Macs that support 802.11ac yet.
On to the speeds:
I share my full thoughts in the video review (above), but in general the router performed admirably. I really like this thing. In fact, I like it so much that I think it would work really well as a router on its own even though you don’t yet have any 802.11ac devices. It’s got dual radios to support 5GHz and 2.4GHz simultaneously, its stock (Buffalo) firmware supports running a VPN server right out of the box, and it even has a USB port for sharing a USB drive with the network (though it only supports FAT-formatted devices, not HFS+). That VPN server puts it ahead of the Airport Express, which only has “Back To My Mac” support and doesn’t (yet?) allow devices like iPads to connect to the network. More detailed thoughts and opinions are, of course, in the video.