The Asus S400CA has an 802.11n WiFi standard which is better than most laptops that have been on the market for around the same time as it. Most laptops that are a comparable age to it have an 802.11b WiFi standard. This notebook PC also has an 802.11g WiFi standard.
An 802.11n WiFi standard is actually the best Wi-Fi standard amongst all notebook PCs of this type and age.
Amongst similar types of laptop the worst Wi-Fi standard is 802.11a.