One issue that has plagued many Google Voice users since the dawn of time (or at least since GV became a thing) is how not good the app itself is. Those who use GV as their primary phone number are stuck using the app for things like sending/receiving SMS messages, and up until now, there was absolutely no alternative.
Today, however, Koush Dutta has announced Google Voice SMS integration in CM10.1 with not only the stock messaging app, but also any third party application you may use (GoSMS, Handcent, etc.). This is a pretty big deal to anyone who uses both Google Voice and CM, but may also be incentive for GV users who are tired of the terrible app to give the latest CM10.1 builds a shot.
The process seems to be pretty straightforward – here are Dutta's instructions on how to get it working, directly from his Google+ page:
This comes with no support, and is nowhere near complete.
0) Google Voice must be installed with notifications enabled (for now).
1) Install a recent +CyanogenMod nightly. July 1st or later. You need the SMS middleware patches I put in for PushSMS. (see Gerrit)
2) Push this apk to /system/app: http://download.clockworkmod.com/test/babel-signed.apk adb install will not work. The app requires system/signature permissions.
4) Start Babel, choose your Google Voice account. Authorize it.
6) Click the "Accessibility service" button, and it will direct you to settings. Enable "Babel".
No, Babel is not the final name.
How it works:
The app will sync your existing Google Voice messages into your messaging store. New Google SMS will be received as if it were a normal SMS.
When you send a message out from your messaging app, it goes out via Google Voice.
And that's basically it. Dutta notes that this implementation is still in the early stages of development, so you may run into some snags here or there. For Voice users, however, the fact that it's being done at all is impressive.
Koush Dutta (G+)