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 team…
This must be highlighted.
Pick a job based on people that can catapult you to the next levels.