For what its worth...
Bought the EZ-Level with my NN5; does a good job - glad I have it. Intended to buy another when I bought the M1-L but was told not to as it had a tendency to drop off. Now, I use Manforto's leveling center column as my primary levering device; I set the tripod legs to the height I want the camera to be at and then leave them alone. With the NN5, the EZ-Level is my "fine tuning" and adjustor as I move around the circle. I also have Manfroto's leveler, the equivalent to the EZ-Level but it is much more heavy duty (and heavier)(got it before I discovered the leveling center column). Got it out to try with the M1-L and I think it works great for fine-tuning.