They're useful, but not if you do it everytime you get a throw anywhere near their area. They just set up for it and are on auto-pilot. Need to vary it up.
One place I'd like us to use it more is when we're further back and MvE gets the ball really quickly. The striker should be making a run towards that flank so MvE can hurl the ball down the line and we can try and get them on the turn. Chances are most times we'd end up with another throw further up the pitch. Again, not do it everytime but when they look out of position. At the moment we just hold onto the ball, let them get into position and end up playing a shirt throw to a player marked and under pressure.