Pros
TUI are very environmentally conscious, so working in their sustainable development department for a few weeks was a positive experience. Literally everyone was polite and friendly, would take the time to explain things to me, and time out of their day to meet up with me, help on my project work, and even provide advice on my career, and where I could go next. I've always stayed in touch. It doesnt make sense for me (personally) to apply straigh away, but I do hope to return to this company at some point in the future.
Cons
Offices were very plain, and not in interesting locations. (But they do name their office after global capital cities!).