I'm 255 & I don't tiptoe around the trails. Plus the trails here around Philly are super rocky, rooty and rough. If they were weak, they wouldn't last long.
I got mine when I trashed the rims on my 29er and Specialized agreed to warranty them and upgrade to their next higher level, except they were out of stock. Instead, I got a credit for $300 & my LBS got these for me.