Visual voicemail, here. I used GV for a long time with my last phone, but the little quirks added up and were too much.
I'm not a hoarder, and I don't care how much space is available to me: it doesn't justify this new never-delete-anything-ever mentality Google has been evangelizing since Gmail. And permanently deleting GV content is a CHORE, especially if you accidentally let your deleted items fold--uh, label pile up. NO mass delete/empty feature. GV intentionally leaves this out to subtly encourage you to save stuff forever.
Speech to text is mostly just cute. It's not like it works dependably, so leaving it aside, Visual Voicemail is just as free (and again, doesn't require a dozen clicks to delete a message).
Though it isn't mandatory, a lot of people use GV for sms, too. It can be convenient never having to back up texts for a wipe. But MMS is impossible, despite being acknowledged on GV's support site as a requested feature for over a year.
So I'll just keep it simple, kthx.