What's the difference between theoretical and real-life speeds? Keep in mind that whichever router you opt for, advertised speeds are theoretical, and, especially in the case of fast wireless-AC routers, you are likely to never see these speeds in real life. That's due to many factors, including interference, your Internet provider and your network equipment. PCMag.com editor Samara Lynn says if a router delivers close to half of the manufacturer's claim, its throughput is considered excellent.
Distance matters. With all routers, the best performance will be at close range -- within 10 or 15 feet and in the same room. Performance will drop off, sometimes dramatically, with every foot of distance, and every wall or other obstacle that the wireless signal will need to pass through. That can make where you place your router critical -- often spelling the difference between getting a good signal where you need it most, or getting nothing at all. If you have a large home, or one with dense (plaster) walls, you may need to consider a wireless extender or opting for a Wi-Fi system to get coverage to every part.
Wireless-N, wireless-AC or Wireless-AD? Wireless-AC (802.11ac) technology is the best choice right now for most router buyers. Most laptops, smartphones, tablets and other connectable devices made in the last couple of years are wireless-AC compatible, and wireless-AC is backwards compatible for those older devices that you still own and use. Speeds are faster than wireless-N and older routers, and these devices are more feature rich and generally capable. While the fastest wireless-AC routers can be quite pricey, lower-priced, lower-performance wireless-AC routers still out-perform wireless-N models, and some don't cost very much more. That said, if you have mostly older gear, lack a broadband internet connection, and/or have a very modest budget, some ultra-cheap wireless-N routers can make sense. Wireless-AD is the latest standard, but support is limited and while these routers are capable of blazing speed, the biggest benefit will only be seen over short distances and within the same room. What about wireless-G and older routers? Our advice is that if you see one on a retailer's shelves, you should leave it there.
How fast is your Internet connection? Gaudy speed numbers are great, but except in cases where your primary concern is a router to move data between devices in your home, they could be overkill if you lack a high-speed broadband connection that can make use of that. On the other hand, if you get (and are paying for) a high-speed connection (and speeds of 150, 200 and even 300 Mbps are available from some providers), you are leaving bandwidth (and money) on the table if you don't opt for a router that can deliver all of that speed.
Will other household electronics cause interference? Expect that cell phone, microwave ovens, cordless phones and other household electronics may cause annoying interference with a wireless network. If you have a cordless phone that uses the 2.4 GHz band, you can avoid interference by upgrading to a 5.8 GHz or 1.9 GHz DECT phone. Wireless-AC routers and some wireless-N routers can also operate on the 5 GHz band which is less congested, and less prone to issues.