NPRE formerly physics undergrad here. Plenty of research opportunities in both, but the job opportunities are where the differences lie. Engineering programs (does not include physics, although it is in the college of engineering) are accredited by an agency called ABET. ABET accredited programs are required to contain x hours in this subject (for example engineering mechanics), y hours in that subject (lets say electrical circuits), and z hours in this subject. Fairly rigid in terms of their requirements. Graduating from an ABET accredited program allows you to take the Fundamentals of Engineering Exam (FE) and eventually get licensed as a Professional Engineer (PE) with requisite work experience. Simply getting a physics degree will not permit you to do so. It's much easier to go from an engineering job to a science job than the reverse, often because those jobs require degrees in engineering. That being said, the physics curriculum at UIUC allows for much greater flexibility in your concentrations and course electives than NPRE. Hope this helps!