I have a wifi blackspot in my son's roon and for Christmas we bought him a new SmartTV and connected it to his PS3. The connection via WIFI was poor and was also intermittent so playing games like Fifa 13 Ultimate team were hit and miss. I bought the Devolo Mini Starter Kit due to the fact that it was recommended in most decent PC magazines but the main reason was that I have a house built in the 30's and the electrical sockets are on the skirting board and so close to the floor that the bigger devices (and potentially cheaper devices such as the TP Link) etc just wont fit. The average size of the 'normal' devices are around 140mm + Ethernet Cable. With the Devolo Mini its 80mm plus Cables so just fits. Netgear do a similar mini/nano device but based on reviews I opted for the Devolo and ordered the Devices for a combined cost + shipping from Amazon of £68. The delivery was very quick and you plug them in to the electrical sockets and one connects to the Router (I use BT Infinity) and the other in my son's room connected to the PS3 and they work instantly, there is no need for setup/configuration etc. I downloaded the dLan Cockpit software from the Devolo Website to monitor the devices and as soon as its installed it instantly finds the devices.
In terms of speed I get approx 150-160 Mbit/s which is obvioulsy a lot slower than the advertised 500 but the gaming experience in my sons room has seen a significant improvement and the games are now playable online with no drop outs or 'jittering'. I would suspect in a newer house or one with newer wiring the speeds would improve but looking at most review sites I think the speeds I am getting is fairly typical.
I am planning to buy another device for the SmartTV to complete the setup.
As a recommendation for those people who have these blackspots its a real advantage and much better performance than WIFI repeaters but this is from personal experience. If you have Devolo 200 and are thinking about upgrading then just be aware that the increase in speed may not be a significant as you expect.
Overall 5/5 due to the ease of setup and the improvement to the gaming experience.