Interesting comments so far, mostly showing how the options have not paid off. Not surprising really, when you consider the likelihood of so many startups reaching a high valuation, and of those that do not having dilution to make the early options much less valuable.
I've worked in a few startups.
One got VC funding but then died in the 'recession' that followed.
Another remained small, couldn't make useful sales, so got bought by a larger company in that market. The main founder came out of it with a well-paid job at new-co. The rest got some small amount of payback for the IP some time later. That did not make up for the salary sacrifice from working there. Still nice to think the product was done well enough and made sales, but that feeling doesn't pay the bills, or the mortgage.
Next startup showed me how dilution works, and how trust is beaten up by greed. Still have some options in the company that bought the original, but those will only be enough for a few good holidays, not even a car purchase.
Despite the fact that these haven't resulted in big payouts for me, the experience was still good in many parts - creating new products and services, growing teams, and so on.
What I would say is, don't take too much of a drop in salary for those benefits, assume the share options won't amount to much, and make the most of the startup environment.
Oh, and do make sure you continue to give yourself some personal time. What I do regret is the time given to those companies that should really have been for myself and my family. The balance I applied did not work out, for me. A shame, but you cannot be too sure at the time. Optimism is a good thing. Pragmatism and realism too.