What business are your clients in? I tend to think of slideshow transitions as something users find enjoyable only for a very short time. (I run a photosharing site -- http://ourdoings.com/ -- where I recently redid the slideshow to use photoswipe, which works well on touch devices but does not do fancy transitions.)
Our clients are typically churches and small business who like to have banners on their home pages. There's always something "featured" that they want to show off.
