You get what you pay for with the Netgear R6100. While it offers decent performance, its performance clearly pales in comparison with Netgear's flagship router, the R6300.
And while the lack of Gigabit Ethernet is a bummer, the router is compact and easy to use.
If you're looking for an 802.11ac (AC) router that costs $100 or less, at the current price of about $99.99 the R6100 is the only choice and a good one. But for about the same price, I'd recommend the N600 Asus RT-N56U, which doesn't support 802.11ac but offers Gigabit Ethernet and better range. If 802.11ac is a must for you, also check out this list.
Very compact design, plug-n-play setup
The Netgear R6100 WiFi Router is an exciting networking device that, for the first time, brings the price of 802.11ac down to $100. This is a true dual-band dual-stream router, meaning it supports all existing Wi-Fi clients on the market. When used with 802.11ac-enabled clients, it offers up to 867Mbps of Wi-Fi speed. With 802.11n (Wireless-N) clients, which are the majority on the market, its Wi-Fi speed caps at 300Mbps. Other three-stream 802.11ac routers, such as the R6300, offer up to 1,300Mbps and 450Mbps when used with AC and N clients, respectively.
The R6100 is much more compact than the previous model, just about half the size of the R6300. Its design is the same, however, with vertical placement, internal antenna, and no wall-mount option.
The new, much smaller, footprint is great but I'm not exactly a fan of this design because all of the network ports are located on the router's back, inside a rather deep groove, making them hard to access, especially for those with fat fingers. This is not a big problem for most users, however, since generally you don't need to do that very often after the initial setup. In addition to the network ports, there's also a USB port and a power on/off button. On the side the router has a Wi-Fi on/off button and a WPS button. On the front, there are just three little indicator lights for power, Internet, and Wi-Fi.
I found the router easy to set up. You just plug the router in to power and connect the router's WAN port to an Internet source (such as a cable modem) using the included network cable. This cable, by the way, comes with labels that say specifically which end of it should go in to the router and which one should go into the modem, but if you use it the other way around, that works too.
The router comes with two encrypted preset Wi-Fi networks, one on the 2.4GHz and one on the 5GHz frequency band, that share the same name and passkey. Information for these is printed on a label stick on the router's bottom. That's all you need to start using it. If you want to further customize the router, you will need to access its Netgear Genie interface. There are two ways to do this, either via a mobile app (available for both Android and iOS) or a Web browser. In the latter case, from a connected computer, just navigate your browser to the router's default IP address, which is 192.168.1.1. The default username and password are "admin" and "password." I find the Web interface much more comprehensive than the mobile app, which is convenient but only permits customizing a limited amount of settings.
Good set of features, limited mobile app
Like the R6300, the R6100 has a robust Web interface. Using the interface, you can customize all the router's settings, such as changing settings for its Wi-Fi networks -- two main networks and two guest networks (one for each frequency band). There are a lot of customizable settings and features but the biggest one is the OpenDNS-based Parental Controls.
First introduced with the WNR2000 in 2009, Parental Controls works with a free account of OpenDNS. Once an account has been created, you can download and install the Netgear Live Parental Controls Management Utility (available for both Windows and Mac) to associate the router with the account. The software then can be used to manage this feature. You choose between five overall Web-filtering levels: high, moderate, low, minimum, and none, where high means most traffic will be blocked, and none means nothing will be blocked. You can also sign in from anywhere via the OpenDNS Web site to manage this feature of your home router. Oddly, however, you can't use the router's Web interface itself for this job.
Another odd thing about the R6100 is its QoS feature, which generally means you can set the prioritization of the Internet bandwidth for certain clients or application in your home network. This feature of the R6100 can only manage the upstream and not the downstream, which is more prone to bandwidth congestion.
The R6100 has one USB 2.0 port that can host an external hard drive for data sharing and media streaming. I found the router could handle hard drives formatted in FAT32 or NTFS, and its USB ports provide enough juice to power any portable bus-powered external drives. Once a drive is plugged in, its contents will be immediately shared across the network, with everybody having full access to it. But you can also customize the share folders for security or privacy purposes. The router supports the SMB protocol, meaning any computer in the network can browse the shares using a network browser such as Windows Explorer or Finder. Share folders can also be turned into an FTP site for those who want to access them over the Internet.
If you choose to store digital content on the connected hard drive, it can also be streamed to DLNA-compliant network media players. This feature automatically scans the attached external hard drive for digital content, making it available to devices within the network. The router can also automatically scan for new content when new files are added, or repeatedly over a period of time.
The R6100 can be controlled with the same Netgear Genie mobile app used with the R6300. In addition to managing the router's settings, you can use this app to stream digital content to a mobile device, such as an iPad. Netgear Genie also has a feature called Network Map, which shows an illustration of connected clients and their information, and one called Traffic Meter, which allows you to control the router's Internet connection. While I like the app, I find it rather limited; for example it only works on devices connected to the router directly within the router's local network. It would be much better if the app could work via the Internet when you're out and about. Also, using the app you can manage both regular networks, but it can only be used to manage the guest network on the 2.4GHz band.