It's amazing to see people write great reviews of products they never use. One such product/service is Google Voice. The concept of it seems like a good idea. Keep your personal number private and give out only your public number, google voice number, which can change as you see fit.
Unfortunately, there are some problems with their implementation.
1. Google Voice cannot send nor receive picture nor multimedia SMS text messages, at least not on an iPhone. This really sucks and people are not told upfront about this by Google but after using for a little bit who sees the message, "did you get my picture?" and realize pictures cannot be sent nor received through this service. Digging through their support pages you will eventually find this. Had I known this ahead of time, I may not have switched to Google Voice. This takes out half the fun of sending SMS messages.
2. Text message are often lost. I never had a single lost SMS message until I switched to Google Voice. It seems a number of reliable people have told me sent me text messages which I never received. And it never shows up on www.google.com/voice history either. For those who send 1 text a week, it may not be obvious but I send/receive 400 texts a week easy. Having heard complaints enough about missed texts on a consistent basis, I realized Google Voice is not a reliable service. If you are looking for reliability, look elsewhere.
3. International text messaging does not work. When I was using a regular cellphone, I was able to send International SMS text messages without problems. Not with Google Voice. The message you get when trying to send is "destination not supported".
4. Google Voice transcription is not exactly accurate but it is certainly helpful from having to listen to unnecessary voicemails.