My son is busy with the team and also in the orchestra, so he didn’t seek out research this year. But from the stories he tells me, it sounds like the first year students that he knows that DID want to get involved in research have been able to get involved to the extent they desire, and the projects they are working on sound interesting.
He also had positive things to say about the advising in the Cal engineering school; it sounds like engineering advising is very accessible and helpful, compared to his friends’ experiences with L&S advising. The accessibility of joint majors / double majors can also be a plus for someone in MSE which is by nature relatively interdisciplinary. A fairly high percentage of the MSE majors pursue joint or double majors.
One thing to note when comparing schools is that some schools’ engineering majors have a little more space in the curriculum for electives, even though they all cover roughly the same material. This was also a factor in my son’s decision. It can be helpful to plot out the four year curriculum for each school, given what your son would be coming in with (APs / DE credit etc).
Finally, among the materials science programs, I think Cal Poly is somewhat of an outlier not just because of the undergraduate focus of the school, but because the program in this major is so hands-on from day one. If your son hasn’t visited Cal Poly yet, I would suggest that he plan a visit with the department to get a sense of what they do there, since the hands on experience is on a whole different level than many of the other schools. Note that the Cal Poly MATE department is an easier admit than many other Cal Poly majors, so a strong student considering the various UCs that you listed should have a decent chance of admission to this major. Worth a visit 