I have not done mush level bombing, but when the angle speed and altitude was set up correctly, it worked quite well. But cross hair did not drop. Well, to be honest, I ended up doing level bombing manually when I had to many issues with the bombsight not staying at target, lol. One really need a steady flight and farther distance than expected. Both ways, the bombs tend to fall a bit short.
I suppose you use this little asset: http://www.mission4today.com/index.php?name=Downloads&file=details&id=317