I used our new test process, which is also used for testing wireless adapters, to test the WNCE4004 and to retest the ASUS EA-N66. The bridge had its original v184.108.40.206 firmware loaded. There have been no updates. The bridge was placed so that its front side (indicator side) faced the test chamber antennas, which were 8" away. The ASUS RT-AC66U reference router was set to Channel 153 and Auto 20/40/80 MHz bandwidth mode for 5 GHz tests and Channel 6 and 20 MHz bandwidth mode for the 2.4 GHz band run.
The Benchmark Summary shows the averages of all the measurements made in both directions. 2.4 GHz up and downlink results are balanced pretty well. But 5 GHz uplink looks like the WNCE4004's weak spot.
For the throughput vs. attenuation profile plots, I've pulled in the ASUS EA-N66. So this is an N900 vs. N900 bridge comparison. First 2.4 GHz downlink. The ASUS starts with a bit of an edge in the lower attenuations (higher signal levels), but falls off more quickly. Advantage here goes to the NETGEAR.
2.4 GHz downlink throughput vs. attenuation
Same thing happens on 2.4 GHz uplink. Advantage again, NETGEAR.
2.4 GHz uplink throughput vs. attenuation
The NETGEAR's advantage doesn't carry through to the 5 GHz band, unfortunately. The ASUS' strong signal throughput is almost 2X the NETGEAR's. The only good thing for the WNCE4004 is that it does a bit better at the higher attenuations (lower signal levels).
5 GHz downlink throughput vs. attenuation
The result for 5 GHz uplink is similar, except this time the ASUS' initial throughput is 4X higher! It seems that something was preventing the NETGEAR from accessing the higher link rates it needed to achieve the ASUS' higher throughputs.
5 GHz uplink throughput vs. attenuation
The choice between the NETGEAR WNCE4004 and ASUS EA-N66 is clear, depending on your needs. If low cost, good 2.4 GHz performance and connecting multiple devices are your priorities, go for the NETGEAR. If 5 GHz performance is your primary concern and you'd like the option to repurpose your purchase as an access point or repeater, then put the ASUS in your shopping cart.