I feel you on that. It's definitely one of those things where when they "push too far" and it works, you'll never notice, and it "can" be funnier. But, if they "push too far" and it doesn't work, it stands out.

In Chicago, he was a legend. His improv is impeccable. He also lost a fair amount of weight (could be irrelevant though), and although comedy is rather egalitarian, it's no shock that many merely moderately funny performers (men and women both) land roles based on looks.