I've been playing for eleven years. I was never integrated into the grade level system thing or whatever, but I did study classically with a private teacher through the sixth grade in school. I then took a two-year break, came back to the same teacher, wasn't enthused with what I was learning, and stopped taking lessons in February this year. Also, I've never taken theory, but I understand enough to get by.
I haven't improved much in the past couple of years, mainly due to a lack of time and commitment to it. At best, I played the Revolutionary Etude, but it wasn't 100% clean at the written 160 bpm. I keep saying I need to get back to it, but time isn't exactly "of the essence".