My lady friend purchased one of these for our upcoming trip to Italy.  Once I examined hers, I decided not to buy one of my own.  Here's why.

The shoulder straps are VERY stiff.  This is probably because there are two security cables in each strap.  The cables are unnecessarily hard and thick.  So are the straps themselves.

I carry a light daypack.  The straps are thin and flexible.  This allows me to sling the bag over one shoulder with the body of the pack in front of me.  When it is in front of me I can keep an eye on it.  When it is behind me?  Not so much.

The Pacsafe straps are so stiff it would be almost impossible to sling the bag over one shoulder and carry it in front for any length of time.  That is a major minus.  If I carry the bag on my back like a backpack (the way it is intended), anybody can be doing anything behind me and I won't know it.  That's a "nope" for me.

I will add this.  I am a pretty lean, tough guy (paratrooper and marathon man).  I don't worry about somebody cutting a strap and running.  I'll win that one.  That's one reason I'm fine with my light daypack.  If you aren't a fighter--Your Mileage May Vary.