I happen to have all four.
attack and pro are super comfy, skinny jeans fit. Size up if you lift. They pick and pill but are mechanically very durable. Hips vents are the bomb. Knee pads on the pro are less noticeable but also less protective.
sikta are good. Fit is roomier they hold up well too. The timberline is probably closer to the foundDy with the knee and butt reinforcements. They are on the heavy side and cost $$$$. My local dicks and 1 other hunting shop stock Sitka so I can actually try them on.
I bought the foundry last spring so haven’t really worn them. Design seems solid. Slimmer fit than my older corrugates. I like the open (no mesh) hip vents a little less as a concept but I doubt I will mind as much when I put them into practice.
I don’t think you can go wrong with any of them. Unfortunately, I cant offer comments on the FL pants other than prancing around my living room. If I wanted something lighter I would probably go mountain or attacks with a preference for the attacks for comfort. If I wanted something with more protection and durability, Sitka timberlines are an option. The FL foundry seems good too.
i hate to say it, but it is probably going to come down to fit And the only way to know that is going to be order about $1000 worth of pants and prance around your living room to decide and then return most of them. Even within brands, I sometimes order two sizes or end up returning for a different size to get the fit I want.
if you asked me to pick one right know, I would probably say the attacks or pros based on how they fit me and value. I have high hopes that the foundry’s will do well but I won’t know until I get them in the woods.