Adapters are pretty simple beasties, with not many knobs to twiddle. But there are some differences that could sway you toward a particular product, specifically the ability to move the adapter and/or antenna so that you can try to get a better signal and a cable / desktop stand for even more positioning flexibilty. All the adapters in this round-up have buttons to initiate a pushbutton Wi-Fi Protected Setup (WPS) session.
The Wireless Adapter / Bridge Finder calls out both these features and lets you filter for them. The NETGEAR A6200 and ASUS USB-AC53 are the only two products that come with cabled stands. ASUS even throws in another short cable and "NetClip" that lets you hang the adapter off your laptop screen.
The NETGEAR A6200 wins the prize for bendy-est adapter because its USB connector is hinged. This would let you plug it into a laptop, but then raise the adapter body to vertical. You then could swivel the antenna panel to change from vertical to horizontal polarization if you like.
The ASUS USB-AC56 wins the award for unwieldiest adapter due to its honkin' big screw-on antenna. The marketing material describes the antenna s "high-gain", but the gain isn't specified.
The Edimax EW-7822UAC also gets an A for effort with its flip-up antenna. I also like that it doesn't force you to install a client utility to get the driver file installed, like the ASUS and NETGEAR adapters do. It's also the only product in this round-up that has Mac OS and Linux drivers. The Linksys adapter has separate installers for Windows XP, Vista, 7 and 8. But they only install the driver; no utility.
You can read full details of the test process at How We Test Wireless Adapters & Bridges. If you're familiar with our router test procedure, the adapter procedure is very similar. The short form is that instead of having a reference adapter, we use a reference router, an ASUS RT-AC66U, to be exact.
I'm going a bit out of turn in showing the Ranker results first. But it shows I chose the top, middle and bottom-ranked adapters to run throughput vs. attenuation plots on.
AC1200 USB Adapter Ranker result
The 2.4 GHz downlink plot shows the last-place ranked Linksys WUSB6300 having the best performance profile. The top-ranked ASUS USB-AC56 runs between it and the middle-ranked ASUS USB-AC53 except for a few points in the 20 - 30 dB attenuation range. The AC53 has the poorest range of the three since it runs out of steam at 51 dB.
2.4 GHz downlink - Throughput vs. Attenuation
It's a bit tricky to tell by eye, since the plots auto-scale. But the 2.4 GHz uplink plot shows all adapters with lower uplink throughput and the formerly top-performing Linksys dropping to the bottom in the lower attenuation range. At 42 dB, however, it pretty much matches the ASUS AC56 as they head to their disconnect points.