Unfortunately, there does seem to be a lot of confusion regarding the credit card levels and the associated benefits, which leads to a lot of difficult conversations during check-in.

One particular trouble spot is the distinction between "priority boarding" (Group 1) and "Priority AAccess", which is complicated further by the fact that cardholders used to receive Priority AAccess prior to November 2012.

While the Gold card is nice for earning miles, go for the Platinum if you qualify in order to take advantage of the first checked bag fee waiver on domestic flights, plus Group 1 boarding privileges. Then again, there seem to be a lot of agents who aren't too well-versed on the subtle differences between the two cards, so you may be able to get the Platinum benefits with a Gold card simply by arguing with an agent long enough.