Posted for Walter Atkinson <walter@advancedpilot.com>:

 Robert:
 
 Both have been tested.
 
 I have chosen to stay with mags until PRISM is available from GAMI.  The
electronic ignition systems *I* have looked at are not what I want to happen
to *MY* engine.  Advancing the timing at very high power gains you no increase
in power but decreases the detonation margin and places a lot more stress on
the engine.  We demonstrate this on a running engine during the APS class.
 It's a bad idea.
 
 Walter
 <http://www.advancedpilot.com>