I bought the 2L having used the 4L version for quite a while which I really like.
I thought a smaller version of the same bag would be ideal for outings where I only really need some extra pockets for essentials and some extra EDC.
It's mostly served its purpose, but there is one thing which I don't like about the design, and that's strap is that much harder to adjust when you have the sling on your back. I have to actively loosen the loop which can get frustrating, especially since when just wearing the sling, the strap gradually loosens on its own.
I found that this was not an issue on the 4L sling.
Otherwise, this is quite a nice sling that can hold a decent amount for its size. I really like the metal loop for attaching all sorts of things which I store in the back compartment when not in use.