Forget the hassles associated with points and miles, and just go plain old cash back. At best, a $500 ticket will go for 25k miles, so you're getting 2% cashback - but more regularly a $300 ticket will cost 50k miles which is 0.6% cash back. Don't forget the blackout dates, new fees to book using miles, and expiration dates around miles.
The Amex also gives you 90-return policy on everything you buy, extended warranty, and other nice perks. Neither card has an annual fee. This CNN article mentions the cards.