I use the SpinVox voicemail to text service and am a big fan, most of the time.
For those of you who don't know, you set the SpinVox service has your voice mail service. Once it receives messages, it sends a transcription of the voice mail as an SMS or email. No calling your voice mail and navigating through IVR systems. You've also got a written record of the message, perfect if you need to do something in response to the message.
There just two problems. Firstly, when I have to call the voice mail system to listen to a message they weren't able to transcribe (it happens), it hits you like a brick wall, suddenly you're back in IVR hell. Not sure whether this is the delta between the simplicity and beauty of the text compared to IVR; or that I've never learned to use the IVR system because I so rarely have to.
Secondly, and in my opinion more importantly, are the delays in receiving messages. Sometimes it can take an hour or two for messages to come through. Now I hear of deals with the mobile operators to provide the SpinVox service to their customers. If they can't scale up from where they are now, what's it going to be like when those subscriber bases start signing up for it.
I do really love the service, but the delays are infuriating and do take the shine of what is in essence a great service.