and it doesn't matter what level you're at. a good teacher will always find your weaknesses, and solutions to turn them into your strengths.
You know, sometimes that takes more than one good teacher. You have to find someone passionate about teaching before making a long-term committment. I've had some who were good at what they did, they just didn't move fast enough for me. We'd work through X book, and as I'd work up each page, some of them would get this glazed over look in their eye because they would realize they would have to work hard to challenge me. The average teacher usually lasted 3 mos. with me because I really tested their passion to educate me.
I've two-timed (and even three-timed) instructors before, usually setting each one up on a monthly lesson basis. You get a lot of conflicting advice, and after four or five months you have to weed out the teacher or teachers who you think aren't providing you with enough attention. They didn't know they were really being auditioned. Teachers can't stand students who show up unprepared, and yet I would show up for some lessons where a teacher couldn't remember what we had last worked on, and expected me to provide them direction with each lesson. Didn't mean they weren't good teachers, but I didn't wait around for teachers who weren't as passionate as about teaching as I was about learning.
Just an FYI on my own personal experience.