My perception may be skewed by my infrequent use, but strangely math and physics stackoverflows have much less empty posturizing and generally have high quality answers that are thoughtful and helpful. Most matters of "opinon" are limited to the topics that really are matter of personal style - i.e. which textbook is better ("x is better people who prefer y but foo is better if you like bar" instead of the dogmatic "xxx is the only correct book on this topic).