The Deda's (if they are the down sloping ones) really only offer one good hand position - bar ends or hoods (however you want to think of it) and only one brake access position. The flats position is compromised due to their downward slope. Yes, you can use that position sure but it is sub optimal and not designed for it. They also would suck for hill climbing as the hood position is too low. They are made for Tri athletes or TT's who get into an areo position and ride long distances that one way. Usually for Tri's they would be partnered with aero bars. If the bars did not slope like that they would be what are commonly referred to as bull horns. Ok as a bar, but more of an urban thing due to lack of hand positions for alternating over long distances.

The Cinelli's are a basic classic drop bar offering three clear hand positions (flats, hoods, drops) and two brake access options (hoods and drops). You go aero in the drops, climb on the hoods and rest on the flats or switch them all up when going long distance. People will of course have their own opinion as to which position they prefer for what and add more marginal hand position options as well but those are the basics.