Firstly, I use this to send my Sky+ signal to 3 other rooms in my house-kitchen, study and bedroom(upstairs). Some of the walls are solid, some are not. My house is a detached dormer bungalow with no near neighbours.
I bought this 5.8Ghz sender as I had the old 2.4Ghz previously which went nuts when I switched on my wireless broadband, used the microwave, bluetooth on phone etc...this 5.8Ghz system works well when all of the above items are switched on, so there's no distortion or hissing when using this along with the wireless broadband etc. What I would say though is that I've had to play around a bit with the senders/receivers getting a channel that suits and adjusting the aerials on the receivers so that the picture is ok. I live alone so no issues with people moving around but I have noticed that there can be a little distortion when I move around.
If you're expecting crystal clear video and audio then I suggest you pay Sky for an additional connection, but if you're like me and just want an acceptable signal sent to other rooms then I recommend this item :-)
Hope this review is helpful