I'm actually a big fan of both artists, and I do actually think they're pretty even.
When it comes to rapping, Nicki is obviously better.
When it comes to singing, Chris has the upper hand.
Performance skills, that would have to go to Chris.
Discography, they're pretty even. Nicki has more 'high points', but Chris is definitely more versatile and diverse when it comes to genres.
As a business man/woman, which is indeed a 'talent', Nicki is more skilled in building a brand and organising things behind the scenes.
So far, they're even.
But, Chris has the dancing and painting skills which pushes him over the edge.
So, Chris.