I found it difficult, if not impossible, to take advantage of the coupons and couldn't justify the cost so I dumped my World card. Just called them right after they received my full payment and before the new month (and new fee) started. They were very nice about it and wanted to offer me another no-fee card but what they offered didn't appeal to me. I already had the other card (and had received bonuses on both). Also, that final payment was the $4K I owed for a cruise so I got the double points on it.
I have the regular Amtrak card, a Marriott card that gets me Marriott points (with bonus for restaurants). Cruises are rare, air tickets are even rarer. I have 80K+ points having paid and gotten my 3X points for two upcoming rail trips, so I can't see the advantage at this time of keeping that card. Perhaps a Hilton card might be a good deal. I already have a USAA cash-back card.