The one time I got that kind of offer, I got a lot of pressure from the hiring manager to take the most equity possible. They basically insinuated that doing otherwise was disloyal -- although, they cloaked the message in a super-positive tone, saying something like, "we are always really stoked when new hires choose the most equity possible because they believe in the mission". I know those words might sound squishy but trust me, there was no ambiguity about what they meant.

In retrospect I wish I had taken the higher salary.