I work at a start up now after working at the largest software corporation for about two years, and I guess I see the complete opposite. Sure, at the start up, we can dress how we like, show up when we want, etc.. but honestly, people dress the same as they did at the corporation, and people show up at roughly the same time. And I feel (and see) more of a trend of personal responsibility at the start up. With 20 engineers, there's no one to pass the buck to: if something breaks from your area, you fix it. Especially dealing with a live site with millions of customers, versus a two year release cycle at my previous job.

I'm going to have to disagree on the point of expertise too. At my corporate job, I tried bringing up functional programming at a happy hour and got a lot of blank stares. Anything programming related that was not directly related to the job, my coworkers didn't seem to care about. At the start up, people learn different languages for fun and try to stay up with new technology.

I know that all I've done is provide more anecdotal evidence, but my experience has been so 180 degree opposite from yours, Markus, that I felt compelled to comment. I guess the big difference I see is that of passion: corporate programmers are rarely super excited about what they work on, and start up programmers almost have to be. I'm not saying passion means a better product or success, but I'd choose working with passionate people any day of the week.