Great colors and pattern, The quilt on my bed right now is flannel on both sides. No puckers, no problems. It seems to me that the rick is to use the same really high grade of flannel everywhere in the quilt and prewash first. (I was also told not to do curves with flannels. I don't listen very well.) Flannels come in many qualities. Watch out.
Your quilt is beautiful, glad that you don't listen. LOL. Great job.