In another topic Proshow was mentioned as a good slideshow creator program. I looked at the sample videos on their web site and it looked good. But after trying out the free trial version, I'm completely un-impressed. The program is agonizingly slow, and appears that it must pre-render your entire slideshow simply to preview it; unlike Vegas where previewing is an on-the-fly-pseudo render that happens during the preview process.

Are there any other good programs out there that don't suffer from this terrible design flaw?