Without a doubt, Melee aesthetics (sound effects, textures, etc etc) make the game feel much better to melee veterans. From what I can tell on the boards, and in my area, people prefer the melee-look much better. Most of that stuff can only be done in riivolution/ usbloader, but if PMBR can make it happen, that would be a godsend.
Also, if it's possible to make the stitch-face turnip more noticable and to make the stocks look like character faces (like melee) that would be great. Many people have complained that they can't tell if it's a stitch-face, and some people can't recognize their stock count as easily because the little dots are harder to see than character faces
-> This stuff is probably on the backburner as of now though, as the priority lies in character development, character balance, and most of all, making the physics more melee-like.