I've been studying piano since 2002 (well, I studied one year when I was 8 years old). My teacher is a good person, she is not bad mannered, she is gentle, polite, and if she wasn't for her, I wouldn't have increased my piano skills. She doesn't demand too much (doing warming exercises, scales, some exercises before playing my pieces, etc.) and she told me that I have improved since I continued playing piano. Her classes are in her house.
One day, I met a person who is a teacher from a Conservatoire, she told me that I can go with her if I want to improve in the pieces I am playing.
The day when I went to see me, she saw my playing, and she told me that I have no bases to play piano, no technique, that my teacher doesn't teach me properly and she want me to "start" with her from zero: with learning the scales, major and minor, their cadences, at different tempo, etc. and that if I got it, then I am going to play piano pieces that she will be giving me.
Of course, when I play the piano, the persons who listen my piano say that I play nicely, that I play it very good, so that means that in general my piano has a good sound and it's not considered as an uncomfortable noise. Playing piano for me is for having fun, not for professional league, despite thinking about it some days.
I want to improve my skills, but also I don't want to replace my formal piano teacher, she has been very nice to me, and she tries her best to correct me in the pieces I play. Maybe the teacher from the Conservatoire is right, that she hasn't taught me properly like the profesionals, but I have a great respect and love for my teacher, I don't want to replace her as my piano teacher, and besides, if it wasn't by her, I would haven't improved in my playing and played many piano pieces as I have, and the pieces I have chosen to learn and play. What can I do? If I went to the Conservatoire is only for improving and polishing my skills, listen other's opinion and because I am opened to other suggestions, not for changing my piano teacher.
Ah, and also I have been in some way autodidactic since I got my electric piano in my house, but I am not worried about it.