One important thing to keep in mind is that when the EUA runs, if there is only one seat available for upgrade, it will pass on you and go to the next Plat below you (if they're traveling solo). Or if you're the last Plats on the list, it will go to a Gold, etc.

That rarely comes into play because most of the time when it hits you there are at least two or more seats available. But it might happen, so worth knowing about. Once the upgrades are under airport control, however, they will typically upgrade one of you if there's only one seat, or sometimes they'll call you up and ask if you wish to be split or if they should keep moving down the list.