Client wants to use a SIFR font for their entire website. Doesn't seem like a good idea to us. We've used SIFR in the past for headings but never for much more than that.
Anyone have any good technical reasoning or resources describing why this is a bad idea?
I would highly suggest taking a progressive enhancement approach instead of sIFR. CSS allows for custom font-faces to be used and they're fairly cross-browser compliant nowadays. For browsers that do not support font-face, they will simply fall back to some other specified font-family that want to use. The concept is to use more bleeding edge styles in your CSS while still gracefully falling back for browsers without adequate support.
From Mike Davidson's announcement of sIFR 2.0:
I looked at the page and he had replaced every single word with sIFR text… even complete paragraphs and 300-word passages. Do not do this please! sIFR is for headlines, pull quotes, and other small swaths of text. In other words, it is for display type — type which accents the rest of the page. Body copy should remain browser text. Additionally, we recommend not replacing over about 10 blocks of text per page. A few more is fine, but once you get into the 50s or so, you’ll notice a processor and speed hit.
So it's not a good idea. In fact, these days, sIFR itself isn't really necessary (Mike's announcement is from 2005). CSS3's new font features are a much better way to bring awesome fonts to your users.
SIFR is not actively developed anymore (last release dates from 2008: http://novemberborn.net/2008/10/sifr2-0-7-143).
