The Amex accumulates points faster. For example, you earn 12 points per dollar at Hilton properties vs 10 on the other card. Plus, Amex is hands down the best on honoring the SCRA. If you have free time, the points guy is a great blog for this kinda stuff. If you travel a lot, maxing your point potential is worth it. I have like seven credit cards right now and for you doubters, no it hasn't affected my excellent credit a bit. (And yes I pay them in full every month)