We used both US Air and AA, alternating between cards and between Katherine and I. Now just AA. As you said, once you figure it out, it works. Haven't paid for an SXM ticket in last 8 trips. Last October we traveled RT for 25,000 each. Now the best we could do for week after next is 35,000 each RT. There are no direct flights from San Antonio, always go thru MIA. But, no overnights. We leave at 6:30 AM and land 2:20 PM.. Return at 3:15 PM and to SA at about 10:00 PM. Not a bad trip.
As long as the credit card companies keep their games going I'll continue to play.