I have the Plat Amex as well (the fee is $495) and the real benefit for me is the lounge access (AA and US airways), Priority Pass (gets me into lounge when I'm not on AA or internationally) and the $200 airline credit for change fees or food/liquor when I haven't been upgraded because of status.

I know there might be better cards but I don't churn cards for miles so for me the card works well. That said, the guys in these forums can help you do a lot better if you're willing to work for it.