CDI and MSD setups aren't used to keep help u tune into 103.9 Country Classics
As rob said, in times when gap ionization is hard, big boost, lean mixtures, rich mixtures (cold start), low intake charge velocity, WI - i would think achieving the filthiest ball of un shrouded plasma one can muster, would be an advantage. Under normal / lower power figures though; i wouldn't have thought it would make much of a diff, which coincides with testing.
I'm sticking it in my "interweb redneck mod" folder, till i see a single setup that makes MORE power and uses LESS fuel in normal operating conditions, read - "not used to fix an underlying issue"