They say an external frame pack is the opposite of an internal frame pack, and the weight should be low. My son likes the weight low and never complains of sore shoulders. I also like the weight low.

I think it's worth experimenting to find what works best. It's probably different for everyone based on their body and how much weight they are carrying.

The Navy did some studies and found it was more efficient to carry the weight high which would seem to recommend against using a belt. Personally, I don't like much weight carried on my hips as it causes my joints to lock a bit.

Maybe one day, I'll graduate to an internal frame pack for backpacking. I do use an internal frame pack for day hikes.