Just catching up here, but the "getting the 7ER thing out of seniority" discussion... I've got to comment there.
At my peak, I was ~360 out of ~420 on the ATL767. That's a lot of people behind me, and I held a line several months out of the year typically. That's hardly out of seniority.
Had I bid to the NYC 7ER, I would have peaked at ~65% in category. Is almost half way up in category holding it out of seniority? I could have held my choice of various nice trips as a very solid lineholder, though mostly on the weekends... including CPT, AMM, CAI, the occasional PRG, VCE, south america, and various others.
What happened? Well we merged (nothing against the NW guys), and we've reduced service or just don't serve at all piles of those cities. NYC was an all international category up through around 2009. We outsourced many of those cities completely to AF/KL.
I'd still be a lineholder on the NYC7ER, albeit down to around 75% in category-- doing mostly domestic flying. Guess what I used to do a lot on the ATL767? Yep... NYC 757 domestic and local international legs.
Was anyone holding the 7ER out of seniority? Nope. Was getting that senior on a widebody category not the historical norm at DL? Yep, but that doesn't make it out of seniority. Why aren't we holding it anymore? Well... we don't fly to those cities anymore, the airline has been synergized (I'm sure FTB can dig up how many people were on the 767+7ER in later 2008 vs. now), and we've realigned to smaller gauge flying.
Oh, and whoever said that the FAA said to stop putting newhires on the ER, that never happened.