Oftentimes, I have friends that ask me to help them fix their wireless networks. On more than one occasion, they only have one or two computers in their home, so there really is no reason for the network to be slow due to saturation. What I often discover is that they either are a victim of interference in the 2.4GHz wireless spectrum, or they have a low quality/damaged wireless adapter. With laptops, it is usually more of an issue of a low quality adapter because all the major players put cheap network cards in their machines. Other times, especially with desktops and USB adapters, they are simply damaged, which usually involve a bent USB connector.
If they end up needing a new wireless adapter, it is a case of buying the cheapest one available, or buying the next wireless generation (in this case 802.11ac) for future compatibility. Usually, I recommend that they spend the extra money so that they will get the best speeds when they upgrade their router at some point. Some of them even decide to bite the bullet and upgrade their router at the same time, once they realize the potential speed increase over 802.11n devices. Once they have all 802.11ac compatible devices, and realize how much smoother everything is able to run, there is no going back.
The ASUS USB-AC56 and PCE-AC68 use the latest wireless standard, 802.11ac, to provide the highest wireless speeds possible. Both the USB-AC56 and PCE-AC68 wireless adapters are designed with flexibility in mind with removable antennas and accessories to assist in optimal placement. They also support dual-band technology for connection to both 2.4GHz and 5GHz radios. Using 802.11ac means that these adapters can reach speeds of approximately 433 Mbps per stream. The USB-AC56 features two streams, while the PCE-AC68 features a three stream configuration. Additionally, the USB-AC56 adapter supports USB 3.0 to fully support the 802.11ac standards speeds, and both are backwards compatible with previous 802.11 standards.