I don't know if this is a Canadian thing or not as I don't hear much about it from elsewhere in the articles or comments on Windows Central, but you'd have to pay me to downgrade to visual voicemail.
Three of the top four carriers in Canada offer a version of "voice-to-text". The carrier turns the voicemail into text using voice recognition software, and sends it to you as either as SMS, or as an MMS. In the case of the MMS version, the voice message is turned into text but the voice recording is also attached if you want to listen to it. Which I generally don't, as most voice messages are short and the text conversation gives me the gist of it, and I'll probably call back if I need clarification.
I saw an ad for Vonage.ca offering a similar voice-to-text product today.
Voice-to-text is superior as, if I'm at work for example, I don't want to call in to listen to it. But I can steal a glance at an SMS giving me the gist. It rapidly gives me a good idea how important the message is. Without it, I have to listen to the message to know if it's worth listening to. That technology hasn't changed much since the answering machine my family had 40 years ago. Just being able to listen to them in any order isn't a huge upgrade.
So rather than worry about Visual Voicemail, I'd look for a voice-to-text solution. Those are my thoughts for the day.