Vicar, most of the stuff I've heard about tailscrapes have been 767 specific stuff over the last five=ish years with QF.
Whilst we are continuously looking at ways of minimising them and discussion papers bounce around every winter (when the strong westerleys and increased number of x=wind take offs pick up), there is occasionally the tid bit that QF have a similar statisitical number of tail scrapes as other airlines.
I've never heard of one being bad enough to do damage to anything other than the paint work! I've also never read of any incident reports about guys returning due to tailscrape (IE, the first thing they know is when they see the scratched paint on the walk around for the next sector).
The rumours always suggested 'one a week' but again, I've got nothing other than hearsay to back that up. I don't even recall the source.
A few things I know for sure. QF do have them from time to time. We are not perfect (as much as I'd like us to be!) I haven't had one that I know of!