You need a good dual band WiFi router, and here’s why: if you live in a dense neighborhood, chances are high that you’ll experience channel conflict or signal overlapping. In English, your WiFi setup might be very similar to that of your neighbor’s — so similar that everyone’s signals are getting congested (i.e. slow). It’s an issue people are experiencing a lot these days because they are using a router they bought several years ago — usually one that only operates on the 2.4 GHZ band.
With a dual band router, however, you have the ability to make use of the 5 GHZ band. Using a WiFi heat mapping tool (Mac users can give WiFi Explorer a try) it’s fairly easy to see what kind of setups your neighbors have. In my neighborhood, EVERYONE is on 2.4 GHZ and nobody is one 5 GHZ. So for me, switching to 5 GHZ would be like driving on the Interstate with zero other cars to slow me down (whereas the 2.4 GHZ band might be more akin to taking a crowded city street, at least for this illustration).
But newer routers are also just inherently capable of faster wireless Internet speeds. Older 802.11g routers top out at around 54 Mpbs whereas newer, more powerful routers can reach speeds of 1,300 Mpbs — that’s 3x faster!