I never put my purse in the back. It's always either on the seat next to me or on the floor under my legs if I have a passenger.
The
Thermite Versipak does look interesting, and major selling points would be its rugged construction and many pockets. I can't stand having things all in a jumble - when I need to get something, I need to get it NOW!
I'm also a fan of one-shoulder carry. I'm in the process of building a 3-Hour Office Evac Kit at the moment that's a one-strap system for quick grab and wear. One-strap carry does take some getting used to, as it shifts your center of gravity slightly and can fatigue back muscles as you compensate. Keep working with those straps.
Thanks for the excellent review!
~Sarah