I have both a Citi AA card and Chase Ultimate rewards card. I really like Ultimate rewards because the points are so flexible: book hotels or airline tickets directly on ultimate rewards or transfer points to a membership club like Marriott, Hyatt, United, etc. YOu can also buy stuff off of Amazon or just convert to cash and take the money.
I find that this flexibility gives you many options to look for favorable points conversion rates. For example, transfer points into United and book a supersaver awards fare. Round trip to Asia ends up costing around $800 in points equivalent.
If you get the membership fee version, you also get a 7% annual points bonus and 20% off o points bookings through ultimate rewards. So if you spend a lot, I'd go with the membership fee card. Also, the membership card has no foreign transactions fee, which comes in handy when you are overseas.
I've found that I get much better bang for the buck on my Chase points than my Citi American airline points.