Here’s my take on it. I like the look of folding leaf sights. And yes, mine are in fact correctly sighted in for distances engraved on them that is 50, 75 and 100m ;-). They aren’t useless though. I think for practical use a big bore rifle can use one folding leaf in addition to standing shallow V. Combine the V with large popup bead (I believe they are called moon sights) and you have a very fast if inaccurate set of sights, great for fast shooting at a large target, say side on buffalo. Fold over the moonsight and pop the leaf up and you have yourself an accurate set of target sights. I’ve tried to take a photo of it with my phone but it doesn’t really show. The main difference is between the V and the notch. It doesn’t look like much, but is a target vs combat sight difference.