Pros
Truly patient focused. Genzyme was a pioneer in rare diseases when no one else cared. Now even big pharma is in. You felt that your work mattered. Unbelievable products (the ones from rare diseases) that made a huge difference in patients' lives. When there was a supply crisis everyone worked extra hard to get the drugs to the patients. Good compensation and benefits.
Cons
Some Sr Managers from the early days got there by luck and not competence. Poor resource allocation. Too much cash spent on lousy acquisitions that never paid off. That diverted resources away from securing the sustainability of the core business, which was rare diseases. Unfortunately the result was a large drop on the share price, opening the door to activist investors that ultimately sold it to Big Pharma. A pity in my view.