Improvement
1 thing 7 speed players have that 5 speed players don't is touch. On this page is some of the basic and fairly accurate definitions of the rating system I've seen on the internet.
http://www.azpoolscene.com/RatingsDefinitions.html?RatingsForm=7&Safes=10&Kicks=10
5's and 6's just know how to pocket balls, and therefore, often times hit the ball way too hard. Sometimes they do this, because they want that reassuring feeling that they are a 'good player'. Other times, they are just plain showing off for whomever may be watching them.
If you want to move up, there is not other way to do it than to practice, and match up. You must have all the understandings of all the solid fundamentals. If you don't, you will just be practicing mistakes over and over, and therefore will be getting no where.
Someone told me once before, that if you want to be a 10 speed, there are just some things that someone who's been there has to tell you. It has to be the right person too. You will find that the wrong person will only steer you in the wrong direction. Find a reliable pro, or even a BCA Certified Instructor. Don't take instruction from this guy and that guy. Decide to listen to one person and stick with one method. Also, model yourself after one favorite pro. I seriously don't recommend the filipinos (loose & wristy with a long bridge) because that goes against the American style (think Buddy Hall), and besides if you get stuck on Busti's style, you could end up with all the wrong fundamentals.
Good Luck to you, if you want it bad enough, you will get there.