Imho, 5k miles is worth it. The seats are similar to the new F seats on most other domestic narrowbody aircraft. It's no 777 or 747 C.

However, my hunch is that as a premier you're unlikely to clear on SFO-EWR. You're ahead of premiers on discounted tickets but behind Premier Executives and 1Ks.

I like the A319 as far as domestic F goes, because it's a pretty intimate cabin. For transcons I'll generally try to confirm the upgrade in advance b/c as a 1P I often won't clear at the 72-hour window. Red-eyes are usually a bit easier, but with only 8 seats it may be tough. How far off is the flight? What is the load up front?

If you are in Y+ and HAVE THE MIDDLE SEAT NEXT TO YOU BLOCKED you will be almost as happy -- pitch and width will be about the same. And since it's a redeye you're not missing much in the way of service. (You should get a snack in F.. nothing in Y.. but lotsa folks forgo it in order to sleep.)