You forgot. . . .
Ballpoint vs rollerball vs fountain pen
Extra-fine vs fine vs medium vs broad
If a fountain pen, itallic vs non-itallic with a wide choice of nib materials
Size and weight of the pen, itself
I am sure that I have forgotten other parameters
Ballpoint vs rollerball vs fountain pen
Extra-fine vs fine vs medium vs broad
If a fountain pen, itallic vs non-itallic with a wide choice of nib materials
Size and weight of the pen, itself
I am sure that I have forgotten other parameters