I suppose I'll bite too: First, I am an engineer and that is usually spelled s-k-e-p-t-i-c. Second, just based on these forums and word of mouth, SeaFoam is said to be top of the crop for general fuel additives. I have used it sparingly in both diesel and gas engines. It should be great since it is twice the price of most of them. I do not agree to the habit of using fuel additives of any kind on a regular basis. If I have hiccups with small motors (blowers, chain saw, edger, lawn mower, etc.) I admit to putting a gurgle of Seafoam in just in case it will clean/clear/help. Frankly I have never seen proof positive that any additive, no matter how great and no matter what for, was doing any good. Read that "snake oil." Show me the manufacturer that recommends additives -- they don't -- and I consider that fact stronger than 3 or 4 thousand anecdotal miracle stories. There is considerable popularity on the diesel side for the "Power Service" brand fuel conditioner which includes a cetane boost. Claims to prevent fuel gelling in cold temps, curing world hunger, etc.
I'm just not an additive person. If it is going below 10 deg F I will mix in #1 fuel (e.g. kerosene) exactly as the heavy equipment operators up north do. If I am suspicious of some crud in the fuel system I'll throw in a little Seafoam. I have NO experience with the higher tech def chugging, Tier umpty ump super modern diesels. I do know enough not to put anything strange in the fuel with those. Our diesel beetle was a super hero machine until VW caved in to the EPA. Another story.