That's why you gotta send a man to do a rover's job.
We sent unmanned landers to Mars before the Apollo missions, and their data was CRITICAL in designing the lander and choosing landing sites.
It's not some either-or thing.
And for the cost of a single manned mission, we could pave Mars over in Rovers like this.
Frankly, from a PURELY SCIENTIFIC standpoint, and factoring in likely advances in robotics in the next few decades, there's no reason to have any manned missions at all from a strict cost-to-science done ratio.
The problem is that people look at it emotionally rather than rationally. I do support a manned Mars mission because of the emotional aspect.
Even though you'd make a lot more scientific discoveries spending the manned Mars mission money on hundreds or even thousands of rovers, nobody would ever actually SPEND that much money unless it was a manned mission.