I was glad to hear your interest is in the original Theravada, rather than the modern pop varieties of North America. Using the method of first asking "what would you attain if you succeeded perfectly in what you are doing" (God of Many Names, chap. 2) it seems to me that Nirvana must be a total lack of desires, and therefore the end of personality? Vedanta has a similar goal of losing one's personality in the Absolute if one is to escape the wheel of transmigration.
Both those models are in total contrast with the model of the Christian
faith which I live by (see the book on Creative
Love). Love (and all its strong desires) is not eradicated but perfected
in the joys of the heavenly city. Obviously these are images, but it seems
to me that the images reflect very basic different attitudes to us as persons
and what it means to love and be loved.