I have seen a few sites now that use SIFR, and I can see the benefits. I have (quickly) looked into other plugins similar, but SIFR seems to be quite good. So it good in terms of cross-browser compatibility?
I was part of a team that used SIFR in the design of a web application in 2008 so we could get a custom font for headlines.
It works OK most of the time but we frequently ran into problems where the SIFR text would be unnaturally wrapped.
That is
A Headline
Would Look
like This
Whenever this happened, we'd have to have our designer look at it and fix it, usually through some fiddling with the CSS.
The other thing I don't like about SIFR is the way the content flashes or blinks as it's replaced. This is really hard to avoid.
All in all, we spent a lot more time fixing SIFR issues that we thought we would, and in the final analysis I don't think it was worth it.
These days, I might look at a CSS-only solution like TypeKit or Kernest.