I enjoyed having something to do with my time over the summer that I felt was advancing my resume. To be honest I also enjoyed the pay.
What I wish was different
As an engineer, I wish that my day to day tasks were more hands on. For the most part I was stuck behind a computer.
Advice
While I didn't enjoy my work, I think the experience was just as beneficial as if I had enjoyed it because it showed me what jobs to avoid when looking for a career.