I have a ton of all three. KUIU makes some great gear, however their customer support and sales are a complete nightmare to deal with. I have ordered several things that came months after the order (which were marked in stock on their website). I have also worked to get some products in before last season, they kept telling me we will have it in stock soon which was apparently a direct lie, this started 4 months before season opened and by the time it did, I never actually got it, so I canceled my order and picked up Sitka's version out of pure spite. (FL didn't really cary anything comparable at the time I don't think)
As a guy who has built multiple businesses, I know how difficult inventory management can be, however customer support and transparency is massive for repeat business. It is clear that KUIU is struggling to operate as they scale, and they are in no way showing grace under pressure. Because of Jason's complete failure on this, I have limited my KUIU purchases to almost nothing at this point.
I don't know anything about his support of SFW so I don't want to speculate on that.
I'm going to be running FL for the majority of all my new backcountry purchases, and Sitka for my waterfowl gear.
As a BCHA member I love the support I see from the FL team, and to be honest it gets me amped to support a group of good guys making great products.