The 2.4GHz frequency is crowded. Not just with neighbors using the same frequency, but also baby monitors, cordless phones, microwave ovens and more. Modern 802.11n routers offer "dualband", which means they're sending two network signals: One at 2.4GHz, and one at 5GHz, which is far less crowded and offers more channels. So why not make the jump to 5GHz and enjoy a less crowded Wi-Fi frequency at higher speeds? Well, unfortunately, many device makers thought it was a good idea to save some pennies on the Wi-Fi chip and go only with the 2.4 GHz receiver.
Here's my advice: Activate both networks and connect the mobile devices to the 2.4 GHz network. Just enable the 5GHz network for your laptops and desktops.