Good Question :)
Talking physically...I think both are inter-related. A healthy heart can function only if the brain is functioning and vice verse. It all ends up with our good physical health.
If talking about your personality whether being brainy is good or being good at heart...then I would chose to have a good heart 'cause I understand people would make a fool of my good heart by tricking me into stuff but eventually it's the KARMA points that I will accumulate and that matters the most in the end!!!