Jim. I've used both, MSD and now Jacob's Omni Magnum.
I can't see any difference between the two, except the "EZ" installation and removal should it fail.
I got a definent improvement as Jacobs said.
My electric fan is a 16 inch puller mod with a thermostat and a control relay.
The relay control voltage is attached to the battery side of the ignition coil. It only runs with the ignition on or engine running.
My W124 has a electric fan in front of the condenser as all M/Bs do with A/C.
This fan has two speeds, the high speed is turned on by the engine temp sensor at 248 degrees F.
I have the new fan on at 200 degrees F.
This combination is working OK.
I'm glad you too believe in ram air induction, 1960 muscle cars had it so why not our Benz.
Happy Trails Beep Beep from two fans Houston(electric that is)
Donald, El Cheapo
I purchased it from J.C.Whitney