Allison Duhwrote a review of Gregory Sula 18L Backpack - Women's on July 22, 2019
Familiarity: I've used it several times
A lot of day-hiking packs have no internal structure, but I am a fan of tensioned suspension-style back panels because it permits air flow around you and contours to the line of your back. This pack is really comfortable, feels very solidly made, and can definitely hold more than just a layer and some snacks.
I do wish it had a sternum whistle or DWR coating. I use the belt as a waistbelt for balance with the pack and not as a hipbelt for weight distribution -- it *will* jump up from your hips as you move, but I didn't mind. I got mine on sale and am very happy with it! For more details and thoughts, check out my longform review at gearbird.net