Bought this after purchasing a Dell Inspiron that I needed to keep secure for university.
The cable seems quite thin, but as an alarm sounds if it's cut, this shouldn't matter too much. By eye, the cable seems about 1m long. It would have been nice to have it a bit longer, but as the cable retracts into the device for storage, this would make it too large.
The motion sensor feature is good. You can choose two levels of sensitivity. Even with it on the most sensitive it can still be moved, but only extremely slowly and carefully. It would take a good hour to carefully move it out of a room, the slightest judder sets it beeping. The only thing I would criticize is that even when it detects movement, unless the movement is continual for 4 seconds, the alarm will not sound (beeps notifying that it has been moved do sound however). The alarm is loud, but not too ear piercing if you set it off accidentally.
The unit is pretty simple to use, and you can easily set a new unlocking code. A little overpriced at £30, but well worth it for the peace of mind.