What do you want to use the bag for? I find that the Mercer satchel is a great every day bag, while for me the Lorca is more suited for an evening bag, due to the smaller size.
I have never seen the Lorca IRL but I have a black Mercer Nico hobo. The leather is incredibly soft! I agree with pseub, the Mercer satchel is the perfect size for everyday...
Both are wonderful bags but in my mind it would be strictly based on size need. A Mercer can hold it ALL. A Lorca can hold SOME but not all. You really need both...
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