Most of my rulers are still "usable" -
I have some of the Creative Grids ones - it seems that they have "improved/changed" them since I bought mine. I feel that the ones that I have are very "busy" and i really needed to concentrate when I was using them.
The only rulers that I have that I actively dislike are the Quilter's Rule rulers that have the ridges on the bottom side.
The lines are very thick and I feel that interferes with cutting accuracy.