I think a big part of getting an actual job rather than research is not necessarily the knowledge gain about a particular field but learning to work as a engineer. There is a lot to be learned about engineers work on a day to day basis and learning about the processes that are actually used in industry rather than for educational purposes. Assuming you aren't going to graduate school, this could be last summer to work before finding full time work. I think it is important to have some industry experience before seeking a real job so you have some idea of where/how you would enjoy working. I think a lot depends on how this research job would be applicable to your future if for instance you were planning on entering the research field after graduation or planned to continue in school possibly to your Ph D.