For your not inconsiderable money, you get a fairly chunky unit (approx 5" x 3"), an ethernet cable and a nice simple instruction pamphlet. It paired effortlessly with my existing network extenders (TP-Link) within a couple of minutes and did exactly what I wanted it to - turn a TV out in my conservatory into a smart TV. I'm currently playing some BBC iPlayer content (nice Pink Floyd documentary) and throughput speed seems pretty good as there's no buffering. Controls are minimal - on/off switch, link button and LED status lights, which is everything you need.
So why just the three stars? Well because for £10 less than this I got a twin-pack of TP-Link extenders with plug socket throughputs. The BT Hotspot 500 hogs a socket all to itself. On the plus side it does have two ethernet out sockets.
To summarise, this does the job, but there are cheaper alternatives out there with greater functionality.