A turkey done in the roaster oven comes out very moist, BUT the skin will not even be close to what you get in a conventional or convection oven. The lid keeps the moisture in so that doesn't help with crisping and browning the skin.
If the appearance of the bird is important, don't use the roaster oven. If a moist turkey is all you're interested in, then use it, especially if you do the carving in the kitchen.
BTW, make sure it doesn't touch the sides of the insert. The heat comes from the side, so if it touches, it will probably burn in that spot.