1000 vs 1500 elo?

What is the major difference between a 1000 rated and a 1500 rated player. I have been playing chess for quite a while now and reached 1500 just a couple of days ago. Through out this i noticed that even at 1500 some players make mistakes equivalent to a 1000 rated player. The only thing that makes it more interesting is that your opponent and you both have atleast mastered 1 or more openings and there are no more unnecessary exchanges which 1000 players do at the very beginning of the game. What is opinion?