They are not too good with overly excited dogs, especially powerful dogs.

Tinny had one for Flyball before she started training and getting excited about it, as soon as she knew what Flyball was about it was the end of the soft crate (it got shredded).

When really, really excited at Flyball tournies, Gonzo has hamster-balled in the soft crate. But, only a few feet. C; And there's a plastic floor insert that can prevent that, for mine.
Clover has done that before she destroyed her soft crate, it is interesting to watch .