I don't know specifics about this particular typeface (and I haven't been "into fonts" for a while), but Roboto is pretty much another typeface with some Grotesk (e.g. Helvetica) lineage. What can typically said about these sorts of new-fangled typefaces is that they're well-optimized for reading on screens and scale well to smaller sizes (that is to say, good for mobile). A simple example is that the x-height (i.e. the height the lowercase 'x', and thus roughly the height of most of the lowercase letters) is higher than a typeface made, say, sixty years ago. The x-height in this case looks to be about 70% - 75% the height of the capitals, which is pretty darned high.