Why does Galaxy Nexus i9250 official car charger have 700mA instead of 1000mA? I discovered that the official Samsung car charger is rated for 700mA, but my stock wall charger has 1000mA. Is that normal? If I buy the 700mA charger, there's the risk that with the navigator on, the battery will not charge?

Instead if I buy this that has 1000mA, will work with my Nexus? Written on it is "for Galaxy Note", but seems OK. Or will I have problems?
It shouldn't matter which one you get, because the internal charging chip "should" control the maximum charging current. So unless you're planning to use your charger with another device that can charge at a higher current, you're wasting your money (unless they cost the same.) If for some reason, like custom ROM or poor firmware, the charging chip is not operating right, you risk burning the vias on the PCB.