In all of my years of school, including university, I have never experienced a portfolio based grading system. I have also never experienced a checklist grade system. I always received a grade for everything I handed in to my teacher, even those assignments that I would now consider low stakes. This semester we all got to experience this system first hand. This was my least stressful class because of that. There was no fretting about what grade I was going to receive because of the checklist. There was no question about what the final letter grade goal was because of the portfolio. It really spoke to that old saying that the teacher doesn't give you a grade, YOU earn it.
Further, this type of system leaves space for doing plenty of reading and reflection. There is room to revise and improve work and there is time to read and hear other educators' thoughts, reflections, ideas, fails and successes. The readings really invoke independent thinking, and the class system really invokes independence period. I would love to try a similar class approach to the high school level once I become a teacher.