Pros
I worked on a single project for the duration of the internship. The project was managed well, and my internship mentor made sure I knew everything I needed to build the project, and that I had enough time to do write-ups, produce presentations and the like.
Cons
A lot of the technologies the company used were hardly the best thing for the job. Some of them were result of a poor decision somewhere up the line. Others were a good choice some years ago, but slow decision-making prevented them from being replaced. Getting things done took a long time. The fact that the database team was in Australia while I was working there meant that changes to the data model took several days to implement (thankfully, they were fairly cautious and didn't implement changes without testing - however, it did make things take longer). The technical culture was interesting, and not in a good way. I was invited to a yearly 'developer conference' where teams that were developing tools for use by other developers in the company gave updates on what they were making. Why I should rely on a yearly conference to learn about the most important tools for my job is beyond me.