My take on it is just the style of bag from a practicality standpoint. I’m not fond of the “messenger” style that has a big flap that has to be raised to get access to the large compartment. I find it a hassle, though it looks sleeker than non-flap styles, unless you’ve already become accustomed to that kind of access to the contents of your bag, you may find it to be a big pain. Since this particular one also has the handle attached to the flap, you can’t just hold it in one hand and get stuff out with the other. You have to set it down. It’s even difficult if you have it strapped across your shoulders, because that’s very thick, stiff leather that will pretty much be like lifting a stiff piece of cardboard straight up in order to get into the compartment - very difficult if you have it on.
I have a canvas bag that came in the choice of flap-messenger style, or top zipper style. I use it every day as I am a city commuter and traveller who uses public transit, so YMMV and all, but if I had gotten the flap one, I would have murdered it a long time ago!
And a 5-pound bag is very heavy, even strapped over the shoulders. Mine weighs 7 pounds with stuff in it, I can’t imagine if the bag alone weighed 5 to start.