I am a Public Health major at UCSD in Revelle College and I couldn't be happier with my overall experience. As with other difficult schools, you get stressed during finals and other exams. However, I can walk to the beach in 15 minutes, I live in one of the greatest cities in the US and everyone here is absolutely amazing.
Now as for classes, all general education classes are huge, lecture sizes are usually between 200-500 students, but most classes also have a discussion. Discussions are smaller sizes, usually 20-40 kids where you can ask questions, go over lecture material or get help for homework. Discussions are taught by TA's who for the most part know the material pretty well.
Classes here tend to be more difficult because they are very fast paced due to the quarter system, but it is definitely feasible!
Most professors here are great, they really are passionate and willing to help you if you go see them.