OK, I have now lived 2 weeks with a brain bag. 1 week with a brain cell (size 3) inside it.
I am in major pain. The lower corner of the brain cell is digging into the small of my back when I use the waist belt.
I am a hefty guy - 6'4", 230 lbs. I have the brain cell clicked in place. I have the shoulder straps loose enough so he waist belt holds some weight. If I tighten the shoulder straps tight enough to lift weight off the waist belt, I find it hard to put the bag on and off, especially when wearing winter layers. Also I think putting all the weight on the shoulders when you have a design that should accommodate waist support is a waste.
I think I understand the problem. The bottom corner of the brain cell is just slightly past the padding on the brain bag and only some cordura is between the hard shell of the cell and my spine.
When I used the bag with a booq sleeve the first week, I had no problems, so it is the placement/hardness of the cell is what is causing the problems.
I would appreciate some ideas on how to alleviate this problem. I really don't want to send this bag to that closet full off useless backpacks I have.
I hope there is a better solution than to stick a sock under the cell.