It's fine for me (tested on a new mac and on old-ish pc) in Chrome, Safari. Firefox and Internet explorer.
Failing that, it might just be that your computer is too out if date for modern browser animations.
If its not your browser, and you just don't personally like the speed of the transition, you'll need to provide some sort of evidence that the current speed is detrimental to the site.
Going off past experience the developers won't make tiny changes like that unless they're provided with compelling evidence to show why it's necessary.