Currently holding the AMEX AP Gold card, $120 annual fee, and I'm looking for advice on switching AMEX cards (or cancel it altogether, depending on the advice I'm getting).

When I first got this card, I signed up mainly to use it as a second card beside my CIBC VISA Infinite, which I use for pretty much all daily personal & business expenses.
I hardly ever use the AMEX card, other than at Costco.

Since I am pretty much throwing $120 out the window, what would you guys suggest I switch to as a second card?
Been considering upgrading to the AMEX PLAT product for the extra 50,000 AP miles, not sure about that though.
I am AC Elite 'til 2013, so lounge access would be covered for this year (which doesn't look like a lot of travel for now, other than personal trips, maybe work travel will pick up again later in the year).

Have been reading through posts regarding this topic, but can't come up with a good strategy, so I thought I'd go public and ask the experts on here.

Any suggestions?