I have never used a rotozip, but agree that you should be able to use it in either direction. If I understand these things correctly they take a pretty small bit so the chance of it getting away from you should be slight. There may be times when the direction you feed could affect the quality of your cut. If your trying to cut up to a line feeding in one direction may have a tendancy to pull the tool into the line while the other direction will try to push it away from the line.

Randy