I prefer using the ruler and cutter on these blocks because the pieces are large enough that I need a good, straight edge to line the next piece up with, and I am folding and trimming before sewing, so it's not held in place if you pick it up to cut with scissors. On the rose, I was sewing and then cutting, and that was faster with scissors.
Two quite different methods to doing it.
I am looking forward to the Hawaii star - it looks neat