The McKinnon bag in the 35L was a nice size however, its external aesthetics didn’t work for me. The Wandrd PRVKE in 31L was the winner based on the roll-top extra room and the more simplified look. Both bags have great storage abilities and can be strapped on carry-on luggage. The Nomatic McKinnon is the better for that as the Wandrd PRVKE strap is very tight to the bag.