if your instructor has his $hIt straight, keep him throughout your training, as he'll be a precious commodity.
i've taken over many a frustrated student's training, over the years, only because they were disappointed with their progress...guess what? their previous instructor sucked.
some of us get it, some don't.
some of us enjoy furthering the craft, not just building time, only because we see the big picture.
i've taken many from zero-hour through ATP, while making them a CFI in the interim.
from personal experience: my private pilot instructor sucked. looking back now, all he had in mind was his next job.
next instructor: IR-A through beginings of FI...taught me to simplify those subject areas that i would eventually have to teach. the most valuable instruction i've ever recieved, hands down.
remindinds of my "official" FI instructor: had his next career move inside of his horse-blinders...guess what? HE SUCKED.
i promised myself i would never end like him, no matter how far i got.