Review (4/5): seems to slow/reduce growth over time
I've tried some other types of these laser hair removal devices and the main difference between this one and the others is that the front piece is cooled to make it cold enough to offset the heat from the laser treatment. You still feel heat from it though, but the cooling effect of the front plate mitigates it to a fair extent.
In terms of effectiveness, I found that this slowed down or thinned hair growth after about three weeks of use. It's important to follow the instructions though as you have to have hair down first. It won't work if there is visible hair growth. The area of effect is a narrow band so it's not ideal for legs. It mainly works well for facial hair or small areas. Also, since laser treatment only works during active hair growth, it's necessary to keep treating repeatedly so that you hit a hair growth cycle.
There is a disposable razor and a pair of wrap around sunglasses included to help you with the treatment. The sunglasses are pretty good, but I still closed my eyes and shielded the top of the laser treatment gun with my hand when using it as the flashes are fairly bright and visible even with eyes closed and sunglasses on. It does take some time to start to see results though so you have to keep at it. This is easy to use though, and it has a lot of flashes available before the light cartridge runs out.