To answer the question above: no, mixte sizes are not comparable, partly because nobody knows how to measure them and partly because the dimensions are just radically different. I think we measured my pink mixte out as a 54, and it's big for a mixte, but it is teeny compared to the other 54s we have around. When it had the original drop bars it was way too small for me.

Deb is wise, and that frame is probably pretty heavy, too.