Continental's a better airline and has better F (in the sense that their domestic F is probably closest to AA domestic F in terms of quality, which is what you'll be experiencing if you're flying F to HNL and CUN); US probably has a better FF program (due to their frequent mileage promotions where you can acquire miles for less than 1 cent per mile), though CO's is pretty good.
I stopped flying HP regularly once it merged with US. My experiences have involved a fair number of planes that are late, dirty of have mechanical issues, enough that I
haven't seen a need to change that.
Alaska Airlines ranked highest in overall satisfaction among traditional carriers for the third year in a row, followed by Continental and American. US Airways was at the bottom of the list.
Both airlines have free domestic upgrades for elites (CO likely has more competition for upgrade), but it sounds like you are simply doing vacation travel and upgrades based on elite status are less important to you.