Hi, I'm contemplating getting a Kifaru for a day sack. I'm looking at the X-Ray or Express but have read a few concerning comments on various online reviews. I'm a short 5' 7'' with an average back. I've seen a few comments that the smaller X-ray sat heavy on the shoulders when loaded up because of it's shorter stature. The alternative is the Express which I haven't seen anyone mention the same problem. Any thoughts or recommendations? Further I understand the Express (non-molle) doesn't have a pouch on top of the lid or inside the lid. Is there anyway a Kifaru pouch can be added securely?