My son has this lego torch (along with a lego police officer torch which requires batteries) and he has used it everyday for the last year and 2 months since he received it as a present. He loves it because it is powered by it's wind up arm instead of batteries so I let him take to bed each night without fear of it being left on all night. A few turns of the arm seems to give plenty of power for his needs. As it is in his bed with him he always has light at his fingertips if he wakes up in the night (he is afraid of the dark) which gives him more confidence as he is in control of the light/dark himeself.

It must be built pretty well as it has been dropped and thrown several times (mostly by his younger borther) and is still in one piece and still working perfectly. As he had another, battery powered one, my son gave the battery powered one to his brother. This means that the two of them can make up games and play happily with just the torches (this has made them a good travel toy for us as they are a toy, teddy and night light all in one.

One point to note: they are very hard and quite sharp - if one kid throws it at the other, it HURTS! This has only happened once and hopefully won't happen again.

Re the comments below:
How bright: I have no idea how to value torch brightness and we no longer have the box to see how many candles it is. Lights up the room enough for him to see but you probably wouldn't want to write an essay by the light.
Price: It varies as with most products. Usually around £10, sometimes in 2 for £15 offers, sometimes as much as £15.
How long does the light last: I have not tested it thoroughly enough to say that x number of arm twists powers it for x amount of time. Son probably winds it up for a minute at bedtime and it lasts until after he falls asleep (which takes 2 mins to 2 hours).
Size: approx 8-10 inches tall.