If the Symposium is the backbone of Plato's philosphy of love, then this is his refining text. Certainly more complex in its ideas, it still appears accessible and even almost domestic.
Plato's characteristic use of the dialogue form works well here as it sifts through the complexities of thought. This is especially good on the idea of active Platonic vision, and contains the beautiful myth of the charioteer and his horses.
Probably not a good first introduction to Plato (I would suggest either the Symposium or the Republic), but critically important both in his own time and for the European Renaissance.