My current method seems to be ok.
If you have a ball shape that bounces with gravity off various objects, you get a nice, realistic look to the movement of the ball, but the sprite itself rotates, which looks odd.
Imagine a nice 3D Max rendered, shiny metal ball.
The last thing you want is the ball rotating visually, because you lose the effect of the reflections.
Ticking the No Rotation box keeps the ball looking like a ball bearing, but the movement of the ball is affected by a considerable amount.
With shapes other than round balls, I can understand why it doesn't matter, but to keep round objects looking 3d, it would have been useful to keep the graphics separate from the physics rotation.
No matter though.
As I say, setting the angle to zero every tick seems to work without a performance hit.