I ordered both the Truxedo and the ISM seals. After looking at the two closely I installed the ISM, which says it is made in the States, and kept the other for a spare till I see how good the ISM holds up. Plus, I didn't do the lower edge so may need it for that.
The ISM went on very easy, even had the little alcohol patches included to clean the tailgate. One tip, on a Ram 2500, you can install the side pieces as one continuous strip by sliding it under the two rubber tailgate bumpers on each side. Makes a WAY slicker install than doing it in three pieces like the instructions tell you to. I also installed the seal with the little bulb like part just off the edge of where the gate meets the bed, to see if that will provide a superior seal. The normal install has that bulb part running right up the bed itself so the gate closes on it and presses it tight to the vertical bed rail. We shall see how long it sticks on there for.