You usually hear players take this approach when they are in their late 20s-early 30s, not 20 years young. I didn't think Felix pitched as bad as his ERA last season. On many occasions, he'd be cruising along for four-to-five innings and one rotten one would ruin his start.
The best stat of all, Felix had the fourth highest groundball-to-flyball in the American League last year. Sinkerballers Chien-Ming Wang and Jake Westbrook were 1 and 2 and Roy Halladay was #3. Felix was well ahead of the #5 guy in Joel Piniero.
Barring arm injury, I still think he's going to have a fabulous career.