at first i almost cried because i thought i wasted all my money, then i started liking it. then for shits i took it off, and i kept reaching for it. it totally replaces the need for the lever up top. it is smooth, and very fast, 2 fps, you will be surprised when you actually shoot two shots in a second but it is very easy. i wouldnt want a leica without one, and i am a right eye shooter.
only problem, sometimes the negatives come out a little bit closer together on the film, but they never overlap.