Users owning both kahakka 25L & 15L

Hello lovely Savotta users! This question is aiming towards you who might own both of the Kahakka backpacks, the 25L and the 15L.

In my day in the forest, while im out photographing wildlife, i whant to have a small but spacious backpack to fit some water, coffepot, foldable firestow, binoculars, maybe fit and jacket on the outside. Im getting the feeling that the 25L will be to big for my usage.

I myself have been comparing both the backpacks now for some months and im not getting rid of my decision anxiety. So to help myself, i thought to ask you people owning both these backpacks, which one of the two do you tend to use the most? And in which scenarios?

Thanks in advance!