Is the OP going it alone, or traveling with family? My family of 4 flew down last June. I jumpseated, while the family was on zeds. Day of travel, the flight showed 12 open in BE, while coach had 50+ open. Not sure how often that flight is weight restricted to this extreme, but at first they weren't going to let any nonrevers on. Then they released 5 seats, and then finally, all nonrevers made it on.

We didn't have to go, and we were just visiting friends. If we had missed a day down there, it wouldn't have been a big deal. If we were going to visit again this July, I would just show up with zeds for UA/DL and QF. Having said that, the US is a popular destination for Aussies and they love to come up here during our summer. Delta still isn't as well known down under and capacity has almost tripled on that route in the last 5 years.

Those same friends just came up to the states a few weeks ago for a visit on DL buddy passes. I watched my friends' flight for about a month before they traveled. I want to say that the flight only booked up 30-50 more seats over that amount of time. BE only booked up about 10 over that time. Their return flight booked even slower and went out with 100+ seats open.

Based on my past experience with this route, I would say that flight will go out with 40+ empty seats based on the availability showing today.

As for rolling the dice to get BE, I've see it go to buddy passes and I've seen it go only to most senior S2s.