So after using the service for about a week and a half now, I think I've decided to wait before entirely committing to it. When I say commit to it, I mean tell all of my contacts that I have a new phone number I'd like them to call/text. I know that they don't need to call the GV number for my phone to ring, but it's a LOT easier to tell people "here's my ONE phone number" as opposed to "call me at THIS number, and text me at this OTHER number."
Anyways, I've decided against it because of a couple of things that GV just can't do YET. MMS is one of them. I know there are other ways to get pictures to people's phones, like email, chat services, etc, but that's the point of using GV, to UNIFY my experience, not complicate it. Also, I use group texting relatively often with friends to plan going out and meeting. I know you can text multiple recipients, but then their replies are just between them and the person they replied to; no one else can see the response. I mean true group texting where everyone can see everyones' responses. Finally, I, like everyone I'm sure, hate coordinating telling people about a new number, and since I'm on contract with VZW, I can't port my current number yet.
So like I said, GV is not for me YET. I would love to make it my daily messaging service, but once it can do what I need. Maybe when it get integrated with Hangouts we will see new features. Maybe some of the features are requested enough that Goog will add them sooner rather than later. Nevertheless, unless they give me a compelling reason to switch now, I'm simply going to wait until I can port my number after my contract expires. Hopefully by then, they have the features I need for a texting service.