I have tried both side by side and am quite familiar with Cordoba guitars in general. Personally preferred the C10. With the Solista you're paying for the "Made in Spain" designation, but you're not necessarily getting more guitar for your money. The C10 is often criticized for being made in China, but who cares if you have a better product? I find the C10 to be more responsive, balanced, and colorful with more comfortable playability for the left hand. The Solista was warm but wasn't all that interesting to me personally. Someone recently made a post in this section remarking how they were surprised to discover they much preferred their C9 over the Espana 45 guitar even though it was more expensive as well.
"Success grants its rewards to a few, but is the dream of the multitudes.
Excellence is available to all, but is accepted only by a few." - Christopher Parkening