Howie Kaywrote a review of Lowepro Flipside 400 AW Backpack on July 15, 2012
1) Not made for backpackers. Uncomfortable and not easily adjustable. It hurts to where it.
2) You have to lay the bag down on its back to open it and get the equipment out. Just great in dirty enviornments and poor weather.
3) If you want to make a better bag, Buy a LLBean Mountainside Backpack 278910 OLYK9( 1200.
It's main features are: Three separate water resistant zipper compartments. An open access compartment for tripod and umbrella. It is easy to adjust with unique strap adjusters at shoulder height. It's easy to get on and off. And it's comfortable. However, it is not made for camera equipment. So, I have to foam it myself. But it has tons of room for anything one might need to carry along.
Questtion, what is the purpose of your bag? Not for backpacking into the rough, I would assume. I certainly wouldn't take it to a wedding shoot, would you?