Thanks a lot coolfish and sfo3388.

I guess in my case, I'm not going for any elite status. I simply have a lot of united miles (from my chase credit card) that I can use. So I would probably use 80k for J. Or if the B fare is not too bad and there is confirmed upgrade, I would do that's as well it's good to know that afternoon flight has more chance

I know this is not CI thread but coolfish.. I see you fly CI as well. Have you used delta miles to fly? Is so, how is the availability for J?