Impress.js & Using HTML5 Data Attributes Instead of CSS Transforms

Question

I've been working on a presentation using Impress.js, and was thinking of adapting it for use on iPads. But I'm concerned about how Impress applies transforms to each slide. Instead of just using CSS, transforms are put in the HTML as data attributes, then applied with Javascript.

This strikes me as an overly complicated and difficult way of doing things. I don't have a lot of experience working with data attributes, though, so I wanted to get some opinions on this. Would it be better to just write CSS normally, or do the benefits of using data attributes outweigh the hassle?