Sounds like you got good advice in the earlier post. I am in a position of doing training runs and running marathons over various abrasive and abusive material. The unvarnished e-glass on my boat has made it easy to do repairs...but...I DO have to make repairs after each run. I'm gonna try to avoid kevlar simply because...I don't know...I'm perverse, I guess.... maybe because everybody says that's what I'll have to use, and for the reasons you've already got. I'm gonna try the s-glass in various layups and see how that works. I think it will work ok. I will still expect to do repairs...but maybe not as much. The guys with kevlar have to make repairs also.