Hereditary breast cancer treatment success rate as high as other forms?

Yes: Matched stage-for-stage, the response rate to treatment is no different for the hereditary or non-hereditary forms of breast cancer. The main difference is the risk of developing a second breast cancer or ovarian cancer: this is why many women with brca+ breast cancer opt for "prophylactic" (preventive) bilateral mastectomy and oophorectomy (removal of ovaries).