See RF interference with Wi-Spy Mini
Interference is a huge drag to your Wi-Fi speeds. inSSIDer Office alone can help you avoid interference with other networks, but you also need to deal with RF interference from non-Wi-Fi devices like baby monitors, security cameras, Xbox consoles, and other devices competing for airtime in the 2.4GHz band.
Luckily, Wi-Spy Mini can see ALL types of interference, and it works with inSSIDer Office to give you information about those pesky non-Wi-Fi interferers. This additional layer of information will help inSSIDer Office assign the most accurate Link Score possible, so you can make an educated decision about each access point.