To me this is the wrong way around. On 8.10, if I turn off hinting, I get the kind of rubbish that you posted from the ubuntu website. Bad kerning, unbalanced lettering, wildly varying density of text when you squint at a paragraph, etc.
Are you using firefox 3.5beta? Ive noticed the beta is very significantly deficient when it comes to font rendering – particularly if you have rgb subpixel rendering turned on. On FF3.0.5 with rgb, antialias, autohint, hintfull, you can barely detect color fringing. On 3.5beta, it looks appalling, particularly light text on a dark background, or when you select text. The balance is OK, but the color fringing is terrible.