My son is a first year MSE major at Cal, and he loves it. He feels that there is a collaborative atmosphere in both materials and mechanical engineering; he thinks the students in both of these majors are friendly and fun. MSE is an extremely small major so it can have more of a close knit feeling almost like going to a smaller school, which some students enjoy. He feels that there’s more of a negatively competitive atmosphere among students in the EECS major (which is a very large major), but that is just his impression. (My son is taking an EECS course and one of his roommates is EECS.)
Some of the clubs have competitive entry simply because a lot of students want to join them, but he didn’t feel that the process of applying was too stressful (he applied to two clubs and was accepted to both). Other engineering clubs are non competitive and accept everyone.
Edited to add: From the schools on your list, my son also really liked UC Davis, Cal Poly, and Minnesota. (He also really liked Oregon State.) He felt that he would have been happy at any of those schools.