There are incentives that come with working at startups like broader job ownership, stock options (long term investment), and agile development. Then there are incentives that are inherent in all Big Corps. like the large bonuses you mentioned, job security and generally acceptable work hours. Choosing between the two really boils down to your own ambitions and value of time off from work.

Personally, I am very happy at a Big Co. because my schedule is flexible and not insanely demanding (45hr/wk).