James - I don't think we disagree. I think one should either go with a frameless or a properly designed framed backpack. If backwards pull isn't a problem for you with frameless, then it isn't a problem (for you).
It's the hipbelt wings and removable stay design that I find inadequate. The stay designs I'm talking about are a problem. They add weight without adding the full benefit of a proper framed design. My bone to pick, is this - if you're going to have a frame, design it properly. It will carry much better with little to no weight gain. I'm not saying they're uncomfortable - they're not. It's just that a proper frame design is noticably more comfortable, even when trying the pack on for just a few minutes.
I'm also not saying I wouldn't use one of those backpacks, I'm just saying I'd prefer to go frameless and lose weight, as, as you've discovered, a pad used as a frame works just about as well for weight transfer as the hoop stays for loads around 20lbs. Preventing torso collapse is about the only thing those hoops are good for, which isn't a problem for lighter loads. However frames have MUCH more to offer than just preventing torso collapse.
I do prefer a lightweight framed backpack, but the only way you'll see me wearing one, however, is if it's properly designed to carry over the vertical center of balance, which means conically-cut and centrally-attached hipbelt, bendable stays/hoop, and solid connections. Unfortunately, there is NOT a single one that is also made from UL materials (DyneemaX, Cuben, etc.) with minimal features. I feel this is a largely untapped market.