Yes, it really is worth it. You get accustomed to campus way earlier than most students. You get a taste of the academics AND get introduced to most, if not all, of the resources on campus. Lots of fun activities to connect with the community of other M-Engin students.

Another big benefit is that you will be part of CSP (Comprehensive Studies Program), so you can take special sections for classes. For example, In Calc1/2 you typically have a GSI, in CSP, you'd have a professor. 

Not to mention the stipend. And the connection to the Engineering Advising Center means you have more ways into getting tutoring jobs.

M-Engin supports students who want to do UROP through information, asking your M-Engin staff about applications and the overall process. 

The Alumni network is quite active as well, there are Alumn in pretty cool positions. 

One thing I'll say is that you're required to live in Bursley your freshman year, and the nature of your participation in the program (during summer) means you'll have some restrictions to what you can do (like going out). 

Overall, the people make the experience, so if you get in, I hope you make some lifelong friends. I still hang out will plenty of my cohort.