The closing of the CRC in the A concourse last year was quite a difficult blow for DL flyers in and out of SEA to take. That was a terrific club and waiting out the delays up there made it much more tolerable than sitting in the zoo near the gates. Don't forget that those A gates that DL uses are all the way out at the end of a very long concourse and hanging out somewhere comfortable can sometimes be a bit dangerous if the departure times change.

That being said, we have used the Boardroom and the President's Club, sometimes both in the same evening waiting for a redeye. The only kicker is that you need to leave much earlier from these locations than you would have from the old CRC. But the PC is probably the best option because it is a bit closer than the Boardroom and is open much later. I have never used the WorldClub so I don't know what the logistics would be from there.