This economic situation is really a kind of hybrid of full-salary and apprenticeship, where you're partially compensated in startup experience. I'm doing it now so I can learn the ropes of an early-stage startup while paying off my student loans. But long term I suspect your EV is better as a founder or cash-compensated so long as you properly invest your cash compensation.
<only-marginally-realistic rant>
Even better is to be one of those VP's who come in during Series C at an already-successful company and somehow make a market-salary and get 10%+ in equity. You know, the fuckers in suits who come in and do nothing.
</only-marginally-realistic rant>