Knots just speak to people for different reasons, most of which I believe are unrelated to function. I just love the round turn and might as well have a short cut on my computer for it because I recommend it so much. But, for most tasks there is likely no real advantage of it (but, now that I have you here--it is one of the very few knots which can be tied and untied under strain. There I go again, sorry about that.)

Although I rarely need it for this purpose, I favor the midshipman's for the same reason as the round turn--because of the awning hitch component of the knot, you can tie it under moderate strain. You can't do that with the other two.