Many people would prefer the NSO since they don't lose out on vested shares upon departure (or get saddled with a massive tax bill). If you have a good chunk of

Many people would prefer the NSO since they don't lose out on vested shares upon departure (or get saddled with a massive tax bill). If you have a good chunk of equity, the outcome can be pretty binary: worth something substantial or basically nothing, in which case the slightly higher tax isn't nearly as important as actually getting a piece.