Alan great question and first let me welcome you to the forum.
The nibs supplied with our components to put it nice are substandard at best. They are made in China for the DIY market not for fountain pen users. Will they write, yes, but do they create a writing experience? No, unless you like scratchy and skipping writing. I have had a few that wrote well but only a handful out of hundreds if not a couple of thousand. I have also been able to tune a few to write extremely well, and a number that I've tried tuning for hours and still ended up with a #2 pencil with a broken tip.
There are two manufactures in Germany that make 85% of the nibs for your higher end pen manufactures Bock and JoWo. Of the two Bock is the most recognized brand by most pen people. Both these companies have been around for years and specialize in nibs. When showing your custom made fountain pen to a fountain pen user the first thing they look at is the nib and when they see the component nib they hand it right back and move on. Up until a while ago we were able to get nibs from My friend Lou Metcalf of Heritage Nibs, that was a big upgrade from the Chinese nibs but they are no longer available so the search for a better nib started. I really did not think I would be able to convince Bock to sell and make nibs to fit our feeds but I got lucky (I worn them down). With a Bock nib on our pens we now are able to show the pen person we are on a par with the big boys.
Hope this answered your question, if you have any other questions do not hesitate to ask.
Newbie here... What makes the Bock more desirably than some other nibs we use?