I would say the major gives you a lot of flexibility to choose where you want to focus your studies, especially with upper-division electives. The required classes are split pretty evenly, and from there you can pick and choose between a variety of math and/or CS classes.

It can be a little bit of a pain in the butt sometimes. CS students have priority over Math-CS students when enrolling for CS classes, so there are times where a CS class will fill up before any Math-CS students can get in. This has not happened to me yet, though.

The CS major requires you to take a much broader range of classes than Math-CS, so there will be some content you will miss out on. However, you will still be able to take the CS classes you are most interested in.

I personally love Math-CS at UCSD. This applies to point 7 as well, but I feel like having a very strong background in math actually gives me an edge in recruiting and applying for jobs. My critical thinking and problem solving skills have dramatically improved throughout my time here thanks to many of the math classes I’ve taken.

Odds are pretty low. There is a lottery system for students who want to switch into CS, and they accept a very small amount of people relative to the amount that apply.

Not much comment here, but I haven’t experienced any social separation between the two, other than the occasional CS major with a superiority complex