Hello! I don't have the backpack but I tried it in the store. The closure annoyed me very much. The strap is very thin. You need to place the strap through the small ring, then place the thin pin through the small hole. It took me forever to do it even when I was looking at it directly. Imagine when you go out and need to open/close the bag, it will drive you crazy.
For me, the procedure is similar to the Belvedere PM because you need to place the 'hole' on the ring, then put the strap through the ring. It also took me forever. It's the reason I didn't get these bags although I think they look very good from the web.
On the other side, the backpack has the drawstring, if you don't mind the bag not closed 100%, then you will be fine.