Is it worth putting the time at a big company like Intuit, or if you were to do it over would you go straight to your own startup?
Depends on where you are in your career. Straight out of college I wouldn't recommend going to most big companies... you'll learn bad habits and not be pushed to do your best work. Join a startup.
"What I did take away from Intuit was an essential skill: How to rapidly test and iterate on ideas until you finally get to an indispensable product."
I found that comment really interesting since I've heard this from multiple current and ex Intuit employees. Given how "hot" the lean start-up methodology is, you'd think Intuit would push this more in their recruiting.