I don't have an Amex Platinum card yet, but I do have an Amex Business Gold Rewards card, and entrance is $50. If you are flying from here to another airport with a Centurion Lounge, the $50 one-time fee is good for both places within 24 hours. I'm going to try this out for my SFO to Dallas trip!
The breakfast buffet here was really good. The lounge is gorgeously and modernly designed, and is a comfortable size, though compared to some lounges like the AA lounge in SFO, it does feel a bit cramped/small. But I'd take this over AA any day. ;)