Luke,..... You're welcome

Jim, I posted the same question on this forum (04/03/2008). Almost every post advocated using it as added insurance against interference.
There was one interesting post that took the view that the filter was masking a basic installation problem and the correction of the installation problem would mean you don't need the filter. This post also advocated twisting the ESC wires to eliminate interference. I'm not an expert in the area so I run a filter as cheap insurance.

Terry