This isn't really a fight between corp and startups. I have seen the smallest startups more organized than the biggest corps. It's always about the people.

Personally, I believe starting at a bigger company has many benefits, even though I would now never join one. Considering you never worked there, I don't think a short experience wouldn't be enlightening. Just to learn the rights and wrongs. Be vary about the teams you're joining, though. Sounds to me like you need to figure out first what kind of dynamic you're looking for.