I used it on a recent website project. It worked great for small forms (3-5 fields), which needed rounded corners and drop-shadows on the fields. It did not wor

I used it on a recent website project. It worked great for small forms (3-5 fields), which needed rounded corners and drop-shadows on the fields. It did not work so well for our dropdown navigation menu, things just seemed to be complicated when combining all the show/hide/hover css for that with the PIE effects. (So we wound up using traditional non-semantic markup for rounded/shadowed background images on the menus, but kept PIE for the more straightforward form fields). Others have reported problems of slowness when used on too many elements in a page, but we never experienced this (because we didn't have "too many" elements on the page). If you're already familiar with how to make IE-compatible shadows/corners by faking it with background images, I'd probably just stick with that. But if you want to forge ahead with CSS3 but also have an easy drop-in solution that gets you 80% there on IE, PIE is a good choice.