Team Nelson...I see nothing wrong with shooting fiberglass arrows, in fact they make quite a bit of sense. In the day everyone shot cedar arrows. When fiberglass arrows came on the scene, the were a big accuracy improvement and much more durable than cedar. I can remember my group sizes being cut in half (still not that great) by switching from cedar to glass, and broken or split arrows were not nearly the problem. They were great for field-roving target practice as they were tough.
When aluminum arrows became available my groups once again were cut in 1/2 over the glass arrows, but the aluminum were easy to bend or ding. Of course they could be hand straightened but I never could get them to shoot true.
No doubt the carbons are great to shoot, they are true, lightweight and durable and fly very fast and flat (for an arrow) all contributing to great accuracy. They are also very expensive as buying a dozen is getting expensive. If you are only shooting under conditions where lost or broken arrows are not expected then I would expect shots/$$ they are no more expensive than other arrows.
Im thinking that if you can buy the fiberglass for the right price they would make a great practice, roving and small game arrow.
Don't expect the accuracy, speed or penetration you can get from carbon which would be my choice for big game or serious target shooting.
Silvertp