The construction is very sturdy (metal, it is completley non-slip, and a good size, so that you can control it easily and accurately. Although I've only used it for a few days, it has worked without fault since the moment I connected it and is very easy to install and use with the software. It was dispatched immediately, and arrived within one working day (I ordered on Friday, it was on my desk on Monday morning).
That's the boring bit, but here's the passion: I can't praise this enough. I've got hours of interviews to transcribe, and this foot control together with some free transcription software (I use Express Scribe) has reduced the time by about 300-400%, and the transcribing is even good fun now. I can't believe I even tried to do it without this pedal, because moving your hands from the keyboard every few words to move a control on the screen is just crazy. If you ever used an analogue audio dictation machine in the past, you'll know what I'm talking about. If you didn't, then you need to experience this to understand just how much difference it makes.
I don't know why every computer doesn't come with one - in fact, my only wish for improvement would be the ability to assign the pedals to functions in other programs.