Thanks to you both. Yeah, on DL you can't buy a ticket on that flight. I could buy a ticket through another airline and then list for DL the day before if it looks good. But the best deals on the other airline are nonrefundable, so I'd lose some $ if I ended up nonreving.

I know buying a tix is safe bet, but like everyone else I like the extra space in business, esp on longer flights. I will be sad to get to SYD and then see that I would have made it . . .