Dez, first two season: 17 games, 108 catches, 1489 yds, 15 TD, 13.8 ypc
CE, first two season: 22 games (so far), 107 catches, 1432 yds, 9 TD, 13.4 ypc
Very similar stats their first two years. Dez's total would be higher if he handn't been injured and missed 5 games his first two seasons. Dez was a better punt returner early in his career than CD is right now.
All in all, slight edge to Dez, but CD isn't far behind at this stage of their careers. CD is a better route runner now than Dez ever was, so he's got that going for him.