Here is what happend to my Sunpak when the wind blew my light stand over. The umbrella was bent but still usable.

IMG_0003 by clemmb60, on Flickr

I have not had any problems with my Vivtar 285 since I replaced the foot.

IMG_0005 by clemmb60, on Flickr

I do worry about my 580EX plastic foot.

IMG_0006 by clemmb60, on Flickr

But the 580EXII seems much better. I would assume the 600EX-RT would be similar.

IMG_0007 by clemmb60, on Flickr