I personally had no trouble at all with Jake Lloyd or Hayden. I thought Jake played a little kid better than most kids would have, and Hayden just nailed it for me. To me, the romance and his turn to the dark side was rendered extremely well. I was in tears when Padme confessed her love to Anakin before being wheeled out into the arena, and I was beside myself with emotion for the enirety of ROTS. I attribute most of that directly to Hayden, Natalie and Ewan.