It really depends on how much whip you're accustomed to putting into your swing. The weight in the head of head-heavy rackets causes the racket to drop after the top of your swing, which basically helps you in the downward motion. It makes swinging at a consistent speed easy. Some players prefer to have more control over their swing speed though, so they opt against head-heavy rackets. There`s more room for error with non head-heavy but greater variation.
Taufik used even-balanced rackets towards the end of his career.