CO: Unless you like paying through the nose, you won't upgrade to HNL or any international destination. Nothing like the worst coach product in the industry, room-wise for that EWR-HNL flight.
NW: Eh. No miles on CyberSavers and also a very stingy international upgrade policy. Coach product is poor.
UA: E+ makes the coach experience for the elite flyer acceptable. Labor issues may ground this airline however. Marginal international upgrade policies.
AA: Upgrade any fare and MRTC. That gets my vote.