Every company is different.
Typically, for small business (start-ups) -
> you get better paid
> you have exposure to more technologies and more hands-on experiences
> Easy to get up close to colleagues and bosses
> More visible hence more responsibility
> Less bureaucracy
> Higher effiency and productivity
> Chances of getting rich (stocks)
With big companies -
> You share work load with others which means more stake-holders
> Less visible. Hard to approach higher managers because of layered structure
> less salary but better benefit package (better coverage of medical insurance,etc)
> Fewer opportunities to learn various technologies and skills
> More people means more office crap and politics
> More red-tapes mean low efficiency and low productivity
> Wanna be a millionair? Forget about it...
Being a professional for so long, I would say there's nothing good or bad, there's always something that fits.
