In the Road to Wrestlemania 28 and 29, Taker's segment were the highest rated segments of the show, even higher than Rock'sTaker was always the guy that worked with THE guy. He was never the main draw at any point in his career. No offense to the mans talent and dedication, but if were talking pure star power, Undertaker was never treated as the top star in any era. He was always behind at least 2-3 other guys.
The Rock became the second biggest, arguably biggest, star of WWE's hottest era since Hogans prime, and the proceeded to have huge sucess in hollywood.
The Rock drew more fans, made more money and has far more mainstream recognition than Taker, even before his movie career took off. I honestly don't see how theres anything to discuss.
When Taker and The Rock were in the same show, Taker's segments used to draw more ratings than The Rock's segments, this is a fact.