Some of the complaints in this blog were mentioned in a post by a google employee 4.5 months ago:
... rest assured, weâ(TM)re working to support SMS messages for all Google Voice phone numbers
It will take some time before Google Voice is fully integrated into Hangouts, and we appreciate your patience along the way.ï
there is also mention of third-party apps which, on android, use various methods to achieve VOIP through Google Voice on the handset, which isnt a feature that Google Voice currently allows (it must route your call via an actual phone call).. these apps have been warned that they will be no longer to do that by May 15th of this year..
im guessing that we will be seeing some changes to Google Voice in the coming few months... maybe even things that make this itworld blog post seem kind of silly.
(disclosure: been using google voice since its first year, wish it could be better... 'breaking up' with it over the stuff in TFA is silly, some of those gripes are silly)