Even if they're the older seats (and depending on when this trip occurs, you might get an updated 772) I'd go with the AA flights. It's a personal taste thing - I don't mind the angled seats all that much, you can pick seats at booking, IMO the food is better, and you don't have to go through the Heathrow scrum.

If you're going to be flying much in the coming year, consider applying for AA's Platinum Challenge, which would have you both at Platinum when you returned, good for decent perks in the year (or more) ahead.

And congratulations!