Shouldn't Sage mode technically beat out kurama mode since Sage mode harnesses the power of nature whereas kurama mode harnesses the power of kurama? Sage mode has no limits since it draws energy from all sources, not just one person, or even just from life. It's just that it takes time to enter sage mode and more time to gather energy from external sources than it does from yourself (or your bijuu).
Though I guess Kurama seems to have an affinity for senjutsu himself, too. (Though this may be Naruto acting through kurama).
KC mode is stronger, because a bijou has a higher chakra cap.
For example, let's made up a number for Naruto's chakra level.
100p, Sage mode will add Nature's chakra to that cap to make it stronger. But once it runs out, it needs to be filed again. But won't drain the existing cap.
it's like an extended battery life.
Kurama is like a power plant. The chakra levels are way higher, so is a way better tecnique. Sage Mode still has it's uses so both modes compliment each other.
