Experiences with exercising startup stock options after quitting?

I'm currently at a startup considering my next move and trying to understand how others have handled their stock options. I have a 90-day exercise window if I leave.

I'm particularly interested in:

1. If you left your startup, did you choose to exercise your options? What factors drove your decision?

2. How did you handle the finances? Did you use your savings or a loan to exercise your options?

I'm trying to find an equity compensation consultant but would love to hear about your experiences and any personal advice you'd share with others in this position.