CS5—about 20 years late to the game—finally gets around to making provision for user-defined arrowheads. But it does so in Illustrator's typical everything-is-a-clumsy-nonsensical-workaround fashion. Absolutey infuriating!
It's bad enough that in order to define a new Arrowhead one has to perform this rigamarole:
1. Open the ordinary AI file named Arrowheads buried in Illustrator's installed location.
2. Create a new Symbol (or edit an existing one).
3. Save the Arrowheads file.
4. Quit Illustrator.
5. Relaunch Illustrator.
After all that, your new or modified Arrowhead is finally available for selection in your drawing file.
According to the instructions in the Arrowheads file:
A horizontal stroked line in the back of the design is used to indicate the placement of the arrowhead and the default scale relative to the stroke weight.
Trying to create a simple Arrowhead consisting of an ellipse at the end of the stroke, the top image below is what I have to do in order to get the result shown at the bottom:
So you have to repeat all that nonsense above just to tweak the position of the end of that stroke. WIth each trial-and-error tweak, you have quit and restart Illustrator in order for the Arrowhead definition to update. That absurd non-interface for this "feature" is bad enough. Adding fury to absurdity, though, one can't make a lick of sense out of the criteria by which to accurately predict the resulting placement of the Arrowhead art.
Even if all of that nonsense worked right, Adobe still just doesn't get it. What part of this is hard to understand? Users need to be able to easily specify a piece of artwork for use as a line ending. We need to be able to position that ending relative to the end of the path. In short, we need to be able to do in Illustrator what your competion has been able to provide for literal decades. This is not rocket science. With all of Illustrator's Brushes and Symbols and live Effects, Adobe can't work out a straightforward solution and decent interface for this simple, basic need?
For example: One typically wants an arrowpoint to end at the endpoint of the path to which it is applied. But one typically wants a ball-end to be centered on the endpoint. In this sloppy, convoluted, workaround treatment you still can't do that. Everything is now inboard of the path to which the Arrowhead is applied, and it seems you can't do anything about it.
Compare that to the ability to position the endTiles of a Pattern Brush relative to the end of a path. Can we please have a trace of consistency, compatibility between features, and elegance in this hideous program, Adobe?
This is "industry leading" functionality? This is worthy of the year-over-year decades-late grossly overpriced updates to this archaic, backward program?
No, this feature is substandard garbage. Rubish. Trash. And it took Illustrator 25 years to get this far!