What are cons to use custom fonts techniques compare to web safe fonts? in terms of
- site performance,
- site maintainability,
- Development time
- screen readers users,
- mobile users,
- low speed users
- Sighted User experience
What are cons to use custom fonts techniques compare to web safe fonts? in terms of
The con is simply that your page will not look the same to anyone who doesn't have your custom fonts.
More info here: http://en.wikipedia.org/wiki/Web_typography#Web-safe_fonts
If you use Font-Face to use custom fonts in the user's browser, you will add overhead in the form of additional web traffic to get the fonts downloaded to the user's browser. However, once the fonts are downloaded to the browser, they are cached so they don't have to be downloaded again.
In regards to sIFR, main cons would be more effort to implement, inconsistent site (for people with flash turned off) and obviously the page load time will be slower. Screen readers can also not read flash, hence they may miss any text that is using this technique. I'd recommend against using sIFR for any body text.
Performance does not matter if your page looks terrible to some of your audience.
You need to weigh your audience and see if it they can all use the special fonts.