Here's a quick writing sample with different nibs. My apologies for the quality, I used the camera on my phone in poor lighting.
This is the
Lamy 2000 with
Medium (M),
Oblique Broad (OB) and
Double Broad (BB) nibs.
None of these nibs have been customised, they're factory default. If you click on the photograph you should be able to make out the differences in the cut.
Nibs come in many styles and are always a matter of preference, and preferences change. I use each of these pens regularly and right now I find the
M boring, the
OB nice because it suits my tendency to write on an angle and the
BB fun because it lays down a lot of ink.
(The inks are Iroshizuku
kon-peki, Lamy
Blue and Iroshizuku
shin-kai in descending order and the photograph does none of them any justice.)