MSD, HEI, or OEM?

I recently changed from an HEI 12 volt module to a Crane 6.

Probably self-evident, but my engine now idles more smoothly, has an average operating temp of 10 deg slower, and most obviously has shown an improvement in gas mileage.

10.5:1, Comp XS242S cam, DC Tach drive dist, Bosch HEI coil. 98 Premium.