Not having any expendable body parts, I was an early adopter of the STX brace. It's important to understand that it doesn't do any active "bracing," but rather is an entirely passive device which weighs almost nothing, and which you can't see or feel, at least on a bike with a fairly upright seating position. It doesn't limit normal head movements, but is there to limit and slow down excessive helmeted-head movement in a crash situation. It has caused little or no interference with my hydration pack, and I have learned to manipulate my jacket zipper through the slot in the front. Comes apart and folds up pretty small for saddle-bag storage, while making off-bike excursions. I'd say if you wear a helmet, you should wear one of these, too.