I think its probably more the shape of one's shoulders that matter for shoulder straps? I've not had an opportunity to try Dan's pack but I've used quite a few packs over the years and never had any use for sternum straps. I remove them after a first test carry whenever I switch to a new pack. I'm not particularly beafy and of average height (at 5'10'') ...
My wife wore the S/M DD40 for a week with a starting load of 12-13kg and found it really comfortable and easy to use. She's 173cm tall and had barely tried the pack on before starting the hike, which was also her first for years.
Her three mild criticisms were that it was hard for her to extract her water-bottle from the right side-pocket, that the back got sweaty and the sternum strap wasn't long enough. Aside from that, she loves it and has claimed ownership
Glad she's liking the pack! We are working on some tweaks for next year that will lengthen the sternum strap and make the right side pocket a bit lower. The sweaty back is just going to be a fact of life with this pack, as any system that avoids that has other downsides I don't like (e.g. moving the weight rearward (affecting center of gravity), and/or less durable meshes/foams).