Update Primo Android TTS:
Out of curiosity and in the interest of testing, I installed the "IVONA" TTS engine from Google Play:
[Please Register or Login to download file]
It, and all available voices are currently FREE (this may not last forever).
Comparison between it and the default Pico:
The two voices I tried (English US and English UK) sound much better, more natural. There is, however, sometimes a short delay before the voices speak.
Both sound pretty good within Primo Android. To switch back and forth between the two I tried, you must change the Voice/Language settings within the Android settings to EnglishUK/EnglishUS and then select the associated voice to be the default for each dialect/accent. Primo Android will switch accordingly (I have both an English US and English UK TTS voice installed in Primo Android, and it really does not matter which one is selected...the settings are taken from the Android settings).