The no advance seat assignment would be a big deal to me, especially for the flight to SXM. We recently booked Delta on frequent flyer miles and were able to pick seats. Like I said, I haven't even seen that basic economy being offered on AA flights to SXM. AA has taken to charging extra for seats closer to the front, which offer nothing other than being closer to the front. I just take a seat closer to the back and get assigned seats with no issue.