I tried the USAA credit card when they gave me a $200 sign-up bonus. The web interface (to pay my bill, check my spending history, etc) was inferior to those of larger banks. Chase, Barclay, Discovercard, Citi all have nicer websites.
The interface was nicer than Fidelity's credit card though! Haven't found any worse than that.
As far as cards go, the rewards are decent (you could get up to 2.2% everywhere, or 5-6% in specific categories).
You could also get a lot more value from a sign-up bonus. Some of the top cards right now give $500-$1000 value from signup bonuses.
Disclaimer: I don't play the churning game very hard, but I do sign up for 1-2 new credit cards each year.