Ratemyprofessor was very accurate in my experience, even more so if you're good at reading between the lines of critical comments. Knowing that positive reviews

Ratemyprofessor was very accurate in my experience, even more so if you're good at reading between the lines of critical comments. Knowing that positive reviews generally comes from the class being easier or negative reviews comes from stricter teaching is still useful, and hardly a severe negative imo. You just need to read what the reviews say (and don't say) and adjust accordingly.