This is a cheap set, and that fact shows up in some areas. The keyboard is a little 'flexible' in the middle if you use the feet, and the mouse battery cover was so loose I had to slip a piece of cardboard in there to keep it in place.
However, they keyboard has a very nice feel, is quiet, and is the first wireless keyboard I've used that has a light for the caps lock indicator. Layout is spot on with everything in the right place. The top row of special keys for volume etc. are really handy.
The mouse is a quite small, so you might struggle if you have sausage fingers. Interestingly, the LED glow from the mouse is not visible, so I presume it must be some kind of more reliable laser or other tracking technology - I've certainly not had any problems on any surface.
I like the physical on/off buttons on the mouse and keyboard.
Considering a unifying receiver on its own costs about a tenner, getting a mouse and keyboard at this price is excellent value.
I might get a larger mouse for extend daily use at the desk, and use the supplied mouse for mobile use. The unifying receiver allows this kind of flexibility and is the best thing about the set.
UPDATE: after about week of use, I've decided the supplied mouse is indeed too small for extensive daily use. I'm starting to get tense and tired wrists, and my hands aren't particularly large. I've just ordered the M510 mouse which is significantly bigger for daily use, and will use the supplied mouse for occasional mobile use. The original 4 star review still stands, but I wish Logitech would make clear how big their mice are, as this is a very important factor for something used so extensively.