I just did. Old spoil tip/quarry near me. set the seat low, had a blast - down some pretty steep drop offs - 10 - 15 foot in places. Long time since I've done that, but great, great fun.
Here's a pic, BTW, of my GT:
Edit: forgot to add, I did a bit more searching, and found on the MTBR review section talk of the Hi 5s being recalled not because of the stanchion but the thickness inside the leg. The danger, apparently, concerned using a disk brake (guessing it wasn't strong enough for the extra force).
Don't know if this is the true reason, but you can read about it here:
http://www.mtbr.com/cat/older-categorie ... px#reviews
Talk of it on page 2 and 3