Current UR student here double majoring in Math and CS (will be a senior in the fall), who is also a Scholar (for music).
I don’t think you could go wrong with either school, but I would think long and hard before turning down UR’s offer.
UR has a really strong physics program and solid math and CS programs, as well. The benefits of UR also include the fact that becoming involved with undergraduate research is really easy and also strongly encouraged, which benefits you when applying to grad schools. You can get involved in research as early as freshman year. In terms of job placements, we have excellent career services and placement in STEM fields. Google regularly recruits from campus, among many other companies. UR’s CS program includes theoretical classes in its core, but the really nice thing is because of the electives in the major, you can really tailor your classes to what you want to do. For example, I’m actually interested in going into crypto and security, so I’m able to take classes like databases, computer networks, operating systems (for the understanding of parallel programming), and computer security to fulfill classes for the CS major. CS majors at UR don’t have any problems finding jobs- most have them lined up well before graduation. Some of the skills you need for grad school or jobs aren’t immediately visible in the title of the classes, but we learn all that is necessary. For example, all CS majors graduating from UR will know at least (in terms of computer skills): Java, C++ and (basic) C, Linux, LaTeX, Data Structures, Algorithms, Computer Architecture, Assembly (at least MIPS), Design/Implementation Programming Languages, test-driven development. That’s just what we learn in the core classes.
Also the Richmond Scholar is a huge deal. You get lots of perks with that you wouldn’t have at Vassar. Priority registration and guaranteed on-campus housing really aren’t something I would give up. You also have the scholar stipend on top of the Richmond Guarantee, so you basically have two guaranteed summers of research/“unpaid” internships (funded by the school) available right there.
Also not true that Vassar is better than UR for getting into grad school. For STEM, what matters is what classes you take, how you do in them, and research experience for getting accepted- that’s not dependent on what school you went to. UR has a small program, so you get to know your professors better and therefore, you’ll have better recs. It’s also not unusual at UR to get your research published which is a huge deal as well.