To answer your other question about the worth of it - YMMV. AA is aggressively marketing them now. If you're going on a big vacation, it's an opportunity to splurge a little and bee more comfy.

IME, the real value comes for people without elite status booking far out or close in. For example, I have a flight on UA in a few days and Economy + seat selection + checked bag was $670. First, including a lay flat on the 777 was $770. I booked the latter in a heartbeat. Even without the layflat, the extra space allows me to use my laptop, which more than pays for itself. Other cases, the difference on TUL-IAH was $45. It was actually cheaper to book First than Y + seat + bag.

With elite status, I wouldn't drop an extra 300 bucks on the difference. However, sans status, it is a no brainer.