Red,
I shoot Easton Epics which are real similar to the Excels I think.
Anyway, they are a great compromise in price to value/function. They are not as tough probably as some other types of carbon but dang, you really have to work at it to break them. I do lose a few every year to rock hits or other hard objects/glances but I also don't cry when I lose one. To me they are "tough enough".
They are the only arrow I shoot. I keep a couple dozen in the 500 and 400 size on hand, cut to 30",
and pretty well cover my bases for all my bows (45# to 55#).
Good luck,
Jim