I think this really comes down to the equity grant and whether or not you think that you can personally move the needle. If you're a junior engineer getting your second job, it's a little bit of a scam to be sold on equity. You probably aren't so good at programming that you'll carry the entire company to success; you're being hired because you're a warm body for cheap. But if you're the CTO or VP of Engineering and you're good at that kind of role, then you certainly have the opportunity to build a team that can do better than the average startup, and thus your equity could really be worth something.