There's a reason I still use Firefox instead of Chrome. Actually, there are a lot. But one sticks out. It's not a massive problem most of the time, but in some cases it is.
It's the way browsers render text.
This is incredibly important. Everything on a webpage—at least, all of the actual information on a webpage—is usually text. A browser's job is basically rendering and positioning text. They do it in different ways.
On Mac OS, we don't have this problem. All text is rendered the same way through the operating system, which literally blurs each letter a bit to make its edges look smooth. It's very easy on the eyes at large sizes, but has been shown to be less legible when read for long periods of time. Not to mention, it isn't exactly true to the font designer's intentions, since it makes the edges of each letter fuzzy. Safari on Windows overrides the system rendering and renders text like it would be on Mac OS.
Chrome uses Windows default rendering with ClearType always (unless the system doesn't have ClearType—e.g. unpatched XP). It's better than no anti-aliasing, which just looks horrible. But it begins to struggle in some areas.
Firefox 4+ and Internet Explorer 9+ use the latest tech, DirectWrite. This is a new technology in Windows 7 that uses the graphics card to accelerate drawing of text on the screen, and provides exceptionally smooth and crisp letterforms. It looks great at large and small sizes, and doesn't blur the text.
Here's what that "Stop Censorship" banner looks like in Firefox 11.0a (nightly build) with DirectWrite enabled. (note: It should look the same in IE 9, but since IE 9 doesn't support rotating objects with CSS, I can't test it).
That's how it should look. Rotating the text should, ideally, not change how it looks. DirectWrite has found a way to accomplish this. ClearType, its predecessor, hadn't. Here's how the same text looks in Chrome 17.0 (dev build).
Look closely at the letters. It's obvious that something's messed up here. This isn't the only example (rotation), where Chrome's text rendering looks bad. If you look closely, Chrome's text just doesn't look as good as Firefox's. It forces the lines of each letter into a one-pixel wide line, despite the original shape. It just looks weird. Most people won't notice, but it drives me crazy. It also has serious trouble rendering eastern language characters.
There's a great gallery here showing some fonts (in Google's own font gallery, no less) displayed side-by-side in Firefox and Chrome. This Quora thread also addresses the problem, which has yet to be fixed by the Chrome team, which—it's worth mentioning—has vastly more people and resources than Mozilla's team.
What prompted me to post this was my friend's comment after he used the same code to put an anti-SOPA/PROTECTIP banner over his site. He said:
"I reduced the rotation to -5 [degrees]. -10 was just killing the font, at least on Chrome."
This just seems wrong to me. A browser shouldn't dictate a developer's actions. It should be the other way around. A browser that forces users to compensate for its deficiencies shouldn't exist. That was the point of Chrome in the first place. But Google's Mac-centric teams just don't seem to care about Windows anymore. That's a mistake, plain and simple. You don't ignore the needs of your largest user base. But, I guess Google can do whatever it wants. It is Google, after all.