We used the "Network" benchmark included in the Passmark Performance Test suite to test throughput between computers using several different adapters. For wireless tests, we used a multitude of devices ranging from standard integrated laptop wireless G of a Dell XPS M1530, the ASUS USB-N53 adapter (2.4 and 5GHz), and ASUS' EA-N66 3-in-1 adapter (also 2.4/5 GHz-capable) and placed them in a number of rooms around our office to simulate a typical home setup. The router was placed on the top of a desk behind a monitor, and the test different locations are described below:
Location 1: 6 feet away (typical 2nd workstation location)
Location 2: 20 feet away, same room (large room/living room or office situation)
Location 3: 20 feet away, 1 wall and 1 half-wall separation (next room performance or cross-office performance)
Location 4: 40 feet away, 2 external insulated walls (through-floor or multi-unit usage
The USB-N53 has very strong performance, especially for its price and being a USB 2.0 device. 5GHz performance gave nearly 90Mb/s across all locations, and we saw an impressively-small amount of performance loss. 2.4GHz performance delivered throughput of just shy of 28Mb/s, which is almost enough to fully-utilize your available bandwidth unless you've got an awesome home/office connection. The range on this adapter is impressive, and it also doesn't hurt that you have the ability to tilt and rotate the USB-N53 however you need to for the best reception. I was a bit surprised to see the built-in Wireless G adapter have slightly higher transfer speeds with both at 2.4GHz, but was equally surprised by how well it competed with the EA-N66 at 5GHz.
The USB-N53 is a high performance adapter, and we've used it for PC gaming and it delivered an experience that was, for all intensive purposes, identical to wired. When connecting via 5GHz, not only is it possible to game without seeing a huge disadvantage, it's basically every bit as good. If you've only got a 2.4GHz router to connect to, you will have a noticeable ping increase which will make gaming less ideal, but it can be done given the available bandwidth, but the type of game will influence how big of a deal the added ping time will be.
Using the soft AP mode, we were able to provide wireless connectivity to devices with lower range because the USB-N53's antennas do provide a significant range improvement over the integrated adapters in most laptops/notebooks. Because of the RT-N66U's impressive range, this required a walk down the street to test.