I have purchased this before traveling which has allowed me to pack both lightly and also allow me to utilize it for flexibility. I used it both for urban and nature and it helps with a lot of space if you are running low. I even paired it with my osprey raptor which helps me pack light for hikes but also have extra room for longer days and important items.
Despite using it about a dozen times, I enjoy using it for those reasons. Though there's things I am very disappointed in. Boundary has always been recognized since day one for their quality and use of material and innovative solutions to looking minimal, functional and durable. Though i found it to be a minimal, and functional - I did not find this particular product to be durable despite the claims.
The EXM Port pack for me start to wear and tear despite this item being in the rain a handful of times (3-4 times), the clip that attaches the sides together opens up and doesnt lock properly at times, finding my bag falling to one side during hikes and cycling.
I would only recommend this if the durability is fixed. Otherwise, I do not see this as a long-term investment for the pack as it wears too quickly.