very interesting chart and information. I would love to see one comparing the stock Ace 150/250/350 coils to the:
8x6" SEF Butterfly and the
10X14 Elliptical DD Excellerator II EQ2
The only other variables I wonder about are the differences in the respective frequencies of the units. The 150 and 250 (6.5khz), the 350 (8.25khz) and the AT Pro (15Khz).