In the US there tends to be competition and/or a sense of snobbery among the individual clinicians themselves. The post graduate training for a PsyD and a PhD is intense, so they are highly skilled, and are probably more adept at dealing with the much more complicated diagnoses. They do all the psychological testing and can diagnose complex cases. In fact in major hospitals all neuropsych testing is done by PsyD or PhD students. Social Workers and Licensed Counselors cannot do this stuff. But for much of the therapy we are talking about on these boards, the quality of the therapy will comes down to the clinician as an individual and not the letters after their names.

A PsyD does have 6 years of clinical training after they get their MA in psychology while PhD's do their clinical work in research/academia. While there may be plenty of PhD's who are good T's, its not a result of their training and probably due to interpersonal skills. Same with Psychiatrists, they are medially trained, not trained in therapy technique.

Social Workers and Mental Health counselors are both Masters level programs and have to be licensed to practice and claim insurance. But, there is some snobbery between them and often a difference in approach. In Social Work Master's programs, they are educated in sociology and then can choose a mental health track if they want to do therapy. So as T's they tend to take society as a whole into account and might focus on external in addition to internal factors with clients. For a Master's in Psychology (and license as an LMHC) the coursework is all about psychological theory and counseling technique and approach. So it's possible you might get some LMHC's who do a little more introspection and less examination of social resources available in your treatment, that kind of thing. Neither degree requires any hours for research. After all this though, it seems like in the end, the best therapists are individual and can't be predicted through what the letters are after their name.