Personally, I would have liked:
True form: a 50/50 humany/dragony form to be used in all content with it’s own unique female and male models that include wings and can wear and mog all mail armor. The models wouldn’t have to be pretty just project strength and power. Think a dragonic version of worgen (but in dragon colors, no human skin tones).
Dragon form: typical or even smaller fully-customizable actual dragon to do the dragonflight mode thing as well as working the same as mounts do in the rest of Azeroth.
Neither of the current forms do anything for me. One is too weird and gangly looking and the other too much of an idealized copycat.
Oh, and pre-Sundering, humans existed but high elves/blood elves did not so neither form should be Blood Elf.
For sources, see: Drak’thyr lore - #6 by Silverleigh-drakthul