The mention that Gilchrist 'keeps brilliantly is a misguided insinuation IMO. He keeps wicket well with brilliance at times, but he is not a brilliant wicketkeeper and never has been.
In answer the topic at hand, in his prime he was not over-rated, but I think he has passed his prime and, while he is still very potent, he's not the player he once was. Also, I think he was lucky not to have faced much quality swing bowling in his career. Then again, a lot of the Australian averages reflect such luck.
Sreesanth said, "Next ball he was beaten and I said, 'is this the King Charles Lara? Who is this impostor, moving around nervously? I should have kept my mouth shut for the next ball - mind you, it was a length ball - Lara just pulled it over the church beyond the boundary! He is a true legend."