I know that boot flex should be determined by riding style, but I'm also wondering how much a rider's weight determines the flex of boot he or she should consider. A salesperson recently told me that a mid-flex boot will feel much stiffer to a light rider than it will to a heavier rider and I'm wondering how true that is. For example, should a freestyle rider who weighs 150 pounds generally look for a softer boot than a freestyle rider who weighs 200 pounds?
I currently have Burton Casas (very low-end), which are a stiffness of 2 on a 10-point scale. Since they are too big, I am looking to replace them but I'm not sure what stiffness I should be looking for. I will never be a seriously aggressive rider, but I do like a little bit of everything: trees, powder, groomers, ground tricks, small jumps. No rails or jibs for me. I am a small woman at 5'0'' and 105 pounds. I need a size 4 boot, which NOBODY stocks, so I will not be trying on boots before I buy. I am currently tracking down all boots that are actually produced in my size and then I'd like to narrow my choices down by stiffness and quality before I launch a full-scale search mission for the perfect boot.
On a scale of 1-10, I'm thinking a 3-5 is a good fit. Unless scales are useless, in which case I'm just screwed all around.
I'd probably go a little stiffer than a 5, say a 6. I say this because boots will break in/soften up after some riding, so to keep it in the all mountain range, which is the riding you seem to like, get it a little stiffer.