Is there any way to get around the way Firefox renders the animations? They're not very smooth.
If you view the animation below in Chrome and Firefox you'll see what I mean:
I find that some fonts don't always animate smoothly in certain browsers, if you are not using dynamic text i.e. it is being pulled form a database I would recommend that you render the text out as a PNG.
If your text has to be dynamic then limit the animation on said text or speed it up, the slower the animation the more you will notice it stutter.
The thing is, I've found images stutter as well.