Carter was better at his peak but his prime didn't last as long.
First 9 years:
Vince: 24.1 / 5.4 / 4.1 on 53.5 TS%, most in the dead ball era
Melo: 24.7 / 6.3 / 3.1 on 54.4 TS%
Vince was 3 years older (22 years old rookie) and took a reduced role afterwards, Melo's 9th year was 2011-2012 so some of his best years were still ahead
I'm taking Vince, better peak/prime
Melo's career resume looks a little better but Carter had a bigger influence on the game
Also want to point out that at 42 years of age Vince is having the most efficient shooting season of his career