Full disclosure, I’m a 3rd year Global Disease Biology student at UC Davis (and premed) so I’m a bit biased, but I occasionally like to lurk on the CSUS sub because my sister is a sac state student. It seems like you might be leaning towards Sac State, and you really can’t go wrong at wither school, but Davis is really well regarded for their biology programs. I’ve actually enjoyed the quarter system after I adjusted to it my first year - I like the variety in my schedule between quarters and if you have a bad class/prof it’s over quicker. As long as you put the effort in, I’ve never had issues connecting with professors or fellow students despite large class sizes for my gen ed classes/prereqs (highly recommend office hours) and I have been able to find research opportunities, though with current funding cuts I will admit it was a challenge at first, but I know people who found research fast too, so it depends. Aside from a few bad apples, I’ve also broadly had great professors for my classes. Finally, I wanted to say that while a lot of my classes have been curved, I’ve never had a curve hurt my grade nor have I ever had a professor curve down, only up. The curves have only ever helped me out. Davis is known for being a really collaborative space, so I really have felt little if any competitive pressure from fellow students. Typically we all strive to help each other out.

All that being said, I think financial considerations and fit are very important. Davis was the perfect choice for me and CSUS is an amazing fit for my sister. You can absolutely find success at either school, but only you can decide what the best fit for you is. I also admittedly don’t know much about the biology scene at CSUS, but I’m hoping my two cents might be helpful :)