Beckham could end up being better, but most aren't realizing the guy may already be at his peak and not necessarily get better results in the future.
He was touted as the most pro ready and it shows off in his route running, but he's not getting star treatment. So once he starts getting doubled consistently, his targets and receptions likely will go down. I personally don't think he's going to get better with his route running and corners will catch on to his tendencies.
Like Dez, he lacks deep speed, but makes up for it with his quickness. Don't know how that will translate when he receives more attention.