I think you are right about that the step needs to be in a good distance from the grip section. You just need to know how high do you normally hold your pens and you'll have an idea if it would bother you or not.
For me the first issue is aesthetics with most pens with a big step. The Metro is still a nice one though.
I mean, like these custom pens:
The proportions are just a bit off, and the step is not for making it more streamline or anything...I'm not really fond of these.
They can be comfortable though.
Well, this one above ^^ has a long grip section but its too narrow... the entire design is out of proportion as you say.
I'd prefer something along these lines:
Its all made in one piece, and is using a Pelikan nib unit. That's the best part about custom pens. There's an endless choice of materials, overall design, and you can add your own modifications. In the end the pen would be unique to your needs.
(The image is not mine).
Edited by proton007 - 2/26/14 at 5:13pm