Lawnboi
WKR
For outright stability the sand is absolutely solid. I can shoot with prone level wobble using my sand as a front rest without issue.Part of the reason I went with them. I really like that feature. I saw a few threads where people were mixing the beads and sand together to get the best of both worlds.
Don’t be afraid to let some fill out, they ship really full, and imo too waxy, they take some break in to become really fluid.
Spex lite fill has a bunch of different fill types to play with, I recently bought a few bags, from light to heavy sand. If you end up down that road that’s where I would go.