Having read around fifty reviews of this device, mostly good, I was hopeful that it would perform as the manufacturer states: I wasn't disappointed.
If you are familiar with setting up the basics of a wireless network, this will give you no trouble, it is easier to set up than a new router, and basically "clones" the set-up of your existing network through running the smart wizard when you first connect to it. After you have run the wizard you can then enter the device, like a router, and tweak it to your settings.
Having run the set-up you will now have 2 wireless networks (the device automatically takes the name from your SSID on your router and adds the _EXT extension to it) you will have one called "MySSID" (probably your downstairs network) and one that is called "MySSID_EXT" (probably your upstairs network)
It is recommended that only devices that are struggling with signal strength connect to the new _EXT network. In fact you can use the same SSID on the new device as your router to have one network name to connect to throughout the building. This may cause issues however as the device is intended to increase the signal of devices in dead spots and would be inherently slower albeit by milliseconds should every device in your network decide to route in through the extender. The new network name is also editable.
The set-up manual is adequate, although I would like to have seen more screenshots of the set-up process and also screenshots of the configuration pages, there are some handy FAQS in the manual if you get stuck and tips for gaining optimal performance.
Don't expect this device to be perfect though, a thick wall in a house is still a thick wall, and positioning of the extender can prove vital if you are trying to obtain a perfect or improved signal, this is also relevant to where your power outlets are, and also where your wife allows you to have it! Like a router it is best positioned away from walls, and if possible off the ground. With a couple of adjustments I found the sweet spot between the router and the upstairs pc and got a green connection (the device has a traffic light colour system for its connection to the router) and full strength on the pc.
Other points of note on the device are it has 4 Ethernet ports on it, so you could have 4 wired devices running off it as well as wireless. It also has a push "N" connect WPS (wi-fi protected set-up) button for connecting to WPS equipped pc's and devices, although it will not connect to your router using this button; only additional devices. There is the standard factory reset paper clip button, which maybe useful should you wish to start-up from scratch again.
If you wished to use this product for a large office or school etc you can have up to 4 of these devices inline to cover every corner of your building.
The build quality is reasonable, perhaps slightly flimsy, I am not a fan of the new shiny black plastic they use for products now, they pick up finger print marks badly and I think the finish could be improved.
You have to register this product before using the telephone support service offered, there is also various documents and updates available from Netgears support sites. The product does have an option to automatically check its firmware update every time you connect to the settings page, which is useful.
Overall this is a great product at a reasonable price for anyone wishing to improve their wireless signal around the house and I would happily recommend it.