I got one kid dorm insurance from NSSI primarily to cover her instrument. The insurance was used twice. When a phone was stolen the insurance covered a refurbished identical phone plus case, taxes, and shipping, minus the small deductible. When a laptop was dropped the insurance repaired it (by mail, and it took a couple weeks, so the decision was to deal with the wonky screen until the semester was over.) Both claims were easy.
With the two claims we ended up about even, and had the piece of mind that her instrument was covered in case of mishap.