TwoBluesMama and Lara, I have a Maxpedition Fatboy aswell and couldn't agree more on it. The bag is very sturdy and looks like it won't be wearing out anytime soon. I've had many people take a strange look at it. Mainly because I'm tiny and look completely innocent so they wonder why i need to carry something so heavy duty.
I've had a guy at work tell me : "That's some solid little bag!", probably because of the big strap. It's definitely not girly, not lady-like, matter of fact, it clashes with the way i dress sometimes but I'm a tomboy anyway...but hell it's absolutely well thought for CCW. The motion to get your gun out feels natural, and by adjusting the strap, you can make sure it's at the right level.
TwoBluesMama, i hear you on the groceries tip. My Maxpedition tends to get heavy (or i tend to get tired), with the gun in,the extra clip, my "ladies" stuff and my survival stuff. Last time i loaded out the groceries, i was tempted to put my bag down. I usually have a lot of groceries bags and narrow steps to climb up before i can put them down. I ended up powering through and keeping the Maxpedition on. I figured if something happened, i'd just drop everything and be ready on my gun.
Although the Maxpedition is a brilliant bag, I am now looking to try and transition to on-body carry. I'll def keep it around, especially rather for summer time when it's harder to concel on me, than in the winter time.