Continuing development - Pen head

I thought it important to create some variations on the pen head image and then critique my work.

No. 1- Too tall and curvy, reminds of an an alien space ship and not a pen head.
No. 2- I like the design apart from the pointed ends, it looks too aggressive. Not a message I want to convey in my logo.
No.3- The top is too wide and the middle is to thin.  The pen head shape isn't obvious enough, when someone looks at my logo I want them to immediately see the pen head shape.
No.4- To straight and rigid, no flow to the shape.
No.5- I really like this design. There's a nice contrast between the straight and curved edges and the tiny circle in the centre acts as a focal point for the shape.
No.6- The shape seems out of proportion, I want my design to have symmetry and also balance.