Dibiase is by far the better in ring performer, has the better look and just has the makings of champion. Rhodes is good on the mic, has great facial expressions, and sells well in the ring. Both are starting to develop into competent hands in the ring.
Presence vs. Personality, Skill vs. Savvy...I'm going to go with Dibiase on this one. His personality will start to emerge as he gains experience and confidence and his in ring ability improves with every appearance. I still can't get past how frail Rhodes appears next to all the main eventers on Raw...it's like watching my skinny kid brother wrapping his body around a 200 pound running back's leg trying to tackle him in a peewee football game.
Dibiase just has the look and demeanor of a champion and is developing the skills to back it up.