I'm not sure that I agree about CX Y vs. Delta Y.

Yes, CX will have better Y service for sure... but their seat pitch felt tighter to me than any DL flight I've been on. (Although the large snoring men on either side of me could have easily been the major factor in my discomfort, rather than seat pitch) It's something that I'd at least look at and take into consideration if those were my options.

I can pack my own snacks, but after 15 hours, an extra inch might make a difference.