Hi Mike! To be honest with you - I have seen pairs from which the male was 6'2" and the female 5'3" - sounds horrible but true! However, I have never seen better dancers and I must say that they look absolutely fabulous, regardless of their huge height-difference.
Personally I think that height isn't a very big issue concerning the way the pair presents itself on the dancefloor. Don't get me wrong: I'm not saying that it's not important, but what makes a good dancer (and with that a pair that looks good on the dancefloor) is not the height, the steps or the model-like-face and/or figure... It's the chemistry between partners and the smile on their face that does the trick.
However, no matter what the chemistry is between dancepartners: posture IS a big issue. *I* am a very tiny person myself, and I have noticed that people whom I dance with hold me closer than others because that way it's easier to sway me around the floor! Not only does it look, but I also get to actually FLOAT
And of course: hold those shoulders and arms up!
"Carpe diem, quam minimum credula postero." - Horace