Difference btwn ENFJs and ESFJs:
ENFJs are educational leaders (thus the desire to help others realize/acheive potential) and ESFJs are social leaders, acting more as master of ceremonies. ESFJs are skilled at always saying the "right" thing, giving the right people recognition in large group settings(According to keirsey).
ENFJs are
role-directive and ESFJs are
role-informative.
I find that this makes a huge difference in the way these two personality types interact with others. ENFJs are comfortable with direct communication, even telling someone what action they would like the other to take. ESFJs (that I know) are always
asking if so and so would do such and such. ESFJs are much less direct...sometimes I find this frustrating cause I don't always translate indirect communication accuratley. However, it has been found that role-directive personalities prefer direct communication and vice-versa.
I think that Role-directive and role-informative styles are hugely defining in personality differences. Among SJs, the T's (both I and E) are role-directive. Among SPs, the T's again. Among iNtuitives its the P or J that is paramount- xNxJ's are role-directive, whether F/T, I/E. Therefore INFJs and ENFJs are the only role-directive personality styles that are Feelings types. I believe this is a huge factor in what gives the ENFJ a different flavor- They are the only Extraverted Feeling type that is role-directive. I know that I still annoy people while telling them "what to do," although I really try to be sensitive to their desired communication preference and I pay attention to reactions. Also, Keirsey says that the ENFJ makes implicit "commands." All other role-directive styles do not have Fe as a dominant function.
I work with several ESFJs and we plan fun acitivities- those ESFJs think of all kinds of things that I tend to forget, like do we have enough chairs for everyone? lol- my head is way too in the clouds and that sort of thing holds no interest for me, but those things are extremely important. I am much better at meeting with clients one on one and finding their strengths, as well helping to increase motivation in acheiving goals.
ESFJs are very, very, very practical and realistic. This can tend to be perceived as boring to some other types once one gets to know an ESFJ, although the Fe makes them extremely charasmatic people who are great at hospitality and small talk.
I am married to an ESFJ. I love him. He keeps me grounded, and my head out of the clouds for at least some of the time.

He sometimes says about my enthusiasm, nothing could be
that wonderful

. ESFJs look very optimistic, but like all SJs if pressed they will tell you that they see the world "as it is," and that optimism that you see is a facade to make life more bearable for themselves but especially those around them.