This is a little experiment I conducted comparing the way different browsers render custom fonts through @font-face. What I found was that the two browsers that displayed them best were IE8 and Firefox 4 Beta. The worst browsers were Opera and Safari. Opera seemed to make the characters extra skinny, and Safari made the characters thicker. Coming in the middle were Chrome and Firefox 3.6 which displayed the text with the correct thickness but with harder edges than the FF4 Beta and IE8. Have a look at the images below for a comparison.

Chrome

Safari

Firefox 3.6

Firefox 4 Beta

Internet Explorer 8

Opera