My hobbying had been exclusively via Google Voice since before Google acquired it, when it was called Grand Central.  I have never had a problem with reliability.  No dropped calls, not missed txts.

However, that's irrelevant to the issue.  AT&T is notorious in NYC for dropped calls and bad service, but that doesn't mean a girl using an AT&T phone number is suspect.

Google Voice turns your cell phone into a 2 line phone.  It allows girls to have a work number without needed a 2nd phone which can be suspicious.  It also allows them to easily block stalkers and such.  

It doesn't matter to me what criteria you use to exclude women from your list.  Feel free to not see girls who have 646 area codes because you prefer 917.  I am not saying you should see girls that use Google Voice.  I am just saying that there is no logical reason to think a girl who uses Google Voice is any less reliable than a girl who picked up a burner phone from her pimp this afternoon.