I'm on the fence between John Bud and Soundguy. After buying a large new bottle of PS this fall, and seeing they changed the doses, I planned to buy Howes next time to be safe. I finished the old bottle of PS with a double dose to summer blend diesel that I am still running. We had -17 and -19 degree nights a few days ago. I started the tractor with no problems (thanks to a block heater too) and ran for hours clearing snow. It was closer to -5 by the time I started it, but I think if the fuel would have gelled at -19 it would still be gelled today since it hasn't reached 20 degrees for a week.
PS has never failed me, but it has failed others. I think my fuel must react well to it, or at least better than others' fuel. I still might try Howes next time, as this new bottle of PS has me concerned (no double dose for winter).