Chic, shabby chic or a bit of a mess?
Leather upholstery is limited by the size of the hide. Probably not that much of an issue on smaller sofas.
Faux leather can have very high abrasion resistance and both can be treated for fire resistance.
Care and maintenance is easier with faux leather. Repairs and colour matching are easier with faux leather, which is important if you under-order/under-specify or just need to buy some more if the project scope increases.