Wireless Performance - more
The main reason you're going to pay $200 for Apple's or anyone else's router these days is presumably to gain access to the high throughput that draft 802.11ac can provide in the 5 GHz band. But the AExAC just doesn't deliver compared to its competition.
For the 5 GHz downlink profile, it manages only 293 Mbps at its highest (with 6 dB of attenuation) compared to the D-Link's 372 Mbps. This sets it up to stay below the other routers and end its run with only 19 Mbps at the 39 dB attenuation point used for 5 GHz range ranking.
5 GHz Downlink Throughput vs. Attenuation
Best case 5 GHz uplink is a bit better at 286 Mbps, best case. But throughput at high attenuation again is lower than the other three products with only 25 Mbps at the 39 dB attenuation point
5 GHz Uplink Throughput vs. Attenuation
The one thing I can say about the AExAC's wireless performance is that it is truly omnidirectional. Look at the comparison of the four runs for 2.4 GHz downlink with the router rotated in 90° increments. This is one of, if not the, most consistent performances I've seen.
Four test runs - 2.4 GHz downlink - AExAC
The 5 GHz test runs have a bit more spread, but are again much more consistent than I usually see. Uplink plots were very similar to downlink.
Four test runs - 5 GHz downlink - AExAC
Variation among the four router positionings tested usually vary so much that I end up choose one of the runs to enter into the charts. But because the AExAC's runs tracked to well, I entered the average of the four runs into the charts in each case.
Closing Thoughts
To sum up, I'll let the Router Ranker detail tell the tale. The AExAC ended up with a #6 rank and total rank score of 5.0 This puts it below all of the current-generation AC1750 class routers, except for the very disappointing TRENDnet TEW-812DRU. It also ranks above Buffalo's first-generation WZR-D1800H, but that is the only AC1750 router that hasn't been retested with the new wireless test process.
Apple AirPort Extreme 802.11ac Router Ranking detail
The details shows that the AExAC might have ranked higher, were it not for its surprisingly low routing performance. Not that almost 600 Mbps of simultaneous routing throughput isn't plenty for most anyone. But compared to other AC1750 products, it earned the rank it got.
It also did comparatively well for 2.4 GHz uplink throughput and range. But for the other six benchmarks that go into the wireless rankings, it just didn't hold up.
Fans of Apple's earlier routers have probably already bought or plan to buy the AExAC. And in the end, it's not really a bad router. But if you are looking for more routing features, Windows file sharing that works and better draft 802.11ac performance, there are better options.