I heard Joel and Jeff talking about sIFR in one of the early podcasts. I've been using it on www.american-data.com and www.chartright.us with some fairly mixed results.
Yesterday I was informed that the first line of text on my website appeared upside down in Internet Explorer 6 without flash player. I'm pretty sure that assessment was wrong, owing to no flash player = no sIFR. But I'm getting some odd behavior on my pages, at least in IE 6, 7 and 8. I only really wanted to use sIFR because my fonts looked crummy on my computer in Firefox.
My question is: if you use sIFR, when do you use sIFR? In which cases do you disable sIFR? When is it better to just use the browser font?
You use sIFR moderately, say for headlines. Try not to use it for links, because links in Flash don't work as well as normal HTML links. It also makes little sense to use sIFR only for text that never changes, an image would work a lot better.
I haven't heard about the upside-down problem in a few years now, but in any case, that's an issue with IE 6 and (an old?) Flash player. In any case, it always makes sense to test thoroughly.
Also, did you look into sIFR 3 lately? It's much improved over v2.