The difference between 7k and 5k is actually not too big, from what I've seen, like you said, itemization is one of the key differences, and also decision making. 5k players have most of the knowledge they need to get to 7k, its just that they don't use it, nor do they actually focus on getting there. The ones that do, they get there.
RE: 5K vs 7K players Part 2