Hello,
if fading is selected the gallery is shown different on desktop computer (fading) and tablets / smartphone (sliding). Best would be if fading would also possible on tablets and smartphones. Since that is actually not possible I would suggest that on tablets and smartphone  sliding would be possible with no delay independent  the time for fading on desktop.

I noticed a gallery with interested features. A combinations of images which are sliding and fading AND very interested text can also be added (sliding and fading). http://fone.it/shop/it/

It might be fine im some improvements of the gallery would be possible.