So, I've been looking into other speech synthesis platforms, because eSpeak is very robotic-sounding, especially compared to commercial efforts (google now, siri, cortana etc). As far as I can tell, the best alternative is flite. Flite's default voice is very robotic-sounding; however some contributed voices sound much more natural than eSpeak. I'm adding the best-sounding one I can find (cmu_us_clb) and packaging it as a separate package; if Saera sees it installed, it will give you the option to use it instead of eSpeak. (I'm not bundling it by default, because a, it's over 25 MB and b, I still need to bundle espeak anyway to generate phonemes for voice recognition of song titles, contact names etc.)

Here is a video I recorded, comparing eSpeak and flite side-by-side on the same outputs. Unfortunately I don't have a proper microphone, so it's just using the camera mic.