Wonderful, beautiful and functional writing instrument.
The Decimo vanishing point is narrower than most fountain pens but not skinny. It's easy to hold and easy to write with for long periods at a time. I got the medium nib, which is smooth as butter. It is one of my favorites out of several others. With the vanishing point it is literally one-hand click open and close for quick notes. No pulling or unscrewing of a cap.