You load the rope by moving the cam down, push the rope in, lift it over the cam, then clip your locking carabiner onto the device and belay loop of your harness, very simple.
If you happen to pay out rope too fast and lock its mechanism, you just release the pressure, by not tugging on the live rope, and start feeding rope again. The camming device is a little more sensitive than the Edelrid Eddy, but again, nowhere near as sensitive as the Petzl GriGri. If by accident you do pull too hard, paying out slack, just release the pressure, the cam will then release, and off you go again. Again, another assisted braking device, where there is no need to put a hand or thumb on the cam to release the pressure to be able to feed rope out. This is a much safer way of belaying.
Camp say that you use the Matik with a thumb on the device if you need to pay out slack fast (see pictures below). But I did not feel I had to do that.