That's a shame the Moto G doesn't have voiceless communication. Still, you could wake the phone and use the normal "Ok, Google" available on all Android smartphones.
I too have been wondering if a Moto G might make a decent upgrade to the 2013 Moto X. My biggest complaints have been internal storage and battery life, both of which the Moto G fixes (if we consider the microSD card a solution to storage). I'm not sure how much I'll miss voiceless communication or the AMOLED screen. I definitely get performance hits on the Moto X, and it's been a bit unstable since the 5.1 Lollipop update. Also, no 6.0 Marshmallow update for the X.
$220 is really a steal for a new phone, though.