What I liked
I was a unique situation--I was not hired as part of the "actual" company-wide intern pool but as a contract worker in an intern role (allegedly, because there was not enough room for me originally but the managers wanted me to come work for them over the summer). Either because of that or because of great mentorship, I got to delve right into company work. I was present at every research/technical meeting my mentor was at, I interacted with my manager on a daily basis, and I was in charge of presenting my own data (as well as my team's data at times) at meetings that sometimes were broadcast to the company headquarters. I believe I got to make great professional connections and really get a feel for what a research associate position would be like. While I was given a greater grace period than a standard hire, I appreciated that other employees would be quick to critique my data or presentations. I'm a better presenter, and better scientist, because of it.