My wife and I went for a few hours this morning. I found it very interesting.
It was pretty much what I expected from a pen show - primarily focused on the collectible brands (Waterman, Lamy, Pelikan, etc), and a lot of vintage.
There were some custom pens there, not a lot. Right at the entrance was a booth with excellent closed end wooden fountain pens.
I knew the focus would be name brand collectors. I did expect to see more ink selection. There were only a couple booths dedicated to ink, and even then their selection was fairly limited.
The show itself has a booth with 300 inks to try out, all in identical pens. They were only selling a show exclusive "Chicago Blue" ink. It was really nice to at least see some of these different inks on paper.
Single day admission is $10. The drive time was a bigger deterrent than the cost. Overall we enjoyed it. I'm glad I went.