Beware of great credit cards
That's all well and good if you're incredibly responsible with your spending, but numerous studies have shown that people who pay with credit cards rather than cash spend more money -- even if they do pay off the balance every month. A card that can add $75 to your retirement account if you spend $5 thousand isn't helping you out if it makes you spend $200 a month more than you otherwise would.
Remember: credit card companies wouldn't offer these great deals if it wasn't in their best interests. They know that, on average, these gimmicks will increase their profits, not the consumer's.
According to CardTrak, 60% of people don't pay off their credit cards every month. With the average credit card rate hovering around 13%, there is no perk in the world that makes carrying a balance a financially responsible thing to do.
Unless you're really sure that using a credit card won't increase your spending, I would recommend going with a no-frills card that won't subconsciously tempt you into spending more with promises of air miles and free toasters. Credit cards destroy more consumer wealth than they create, and I'm highly skeptical of clever plans to use them to better our financial lives.