I've got the Franklin pit. I dont know if I could justify the price where it's at now. I paid 3500+shipping which was maybe 600 bucks the time which was reasonable compared to other pits at that time. 5150 including shipping is still a pretty stout price increase from when I bought the pit. Is it twice as good as the Workhorse? There's no way but I do think it's better, but I'm clearly biased having spent the money. I think the design of the exchange between the firebox and cook chamber is better. I think the semi insulated firebox adds a lot of value and I think the ellipsoid head on the stack side improves the air flow. It also gives you slightly more space compared to the 1969 (not including an upper grate).
I would take that video with a large grain of salt. I don't know what soured Jeremy on the Franklin pit. He's got some kind of bias with Fatstack, clearly. The owner of Fatstack brought him two pits. The other guy in the video owned the 1975. Clearly he's not going to say the Franklin is better. When comparing prices Jeremy would always roll in the shipping on the Franklin price and didn't do that with the other smokers. When I was shopping for smokers I looked really hard at Workhorse. I think they are great pits. Shirley wasn't an option at that time for direct flow. The Millscale pit was over 1000 more than the Franklin at that point.