SteelthumbsI have Pelikan M400 Tortoise, M600 Turqoise, M800 Stone Garden, and M805 Stressman all with EF nibs. Even though they are marked as EF nibs, they have significantly different broadness. Someone might say that it is natural considering the manufacturing process of fountain pens, but I strongly doubt whether Pelikan has any kind of quality control process.
First line is written with M805 Stressman EF, second is M800 Stone Garden EF, and the third is M600 Turqoise EF in the attached image. All with Pelikan 4001 ink and on a regular 80g copy paper (line space is exactly 10mm).