Works much better if you have legible, and preferably elegant handwriting. Some of us learned to type in part because our handwriting was illegible and it hasn't gotten better.
Getting unlimited data just to support picture texts? Sounds more like a reason not to send pictures through the phone network. (Yeah, in this regard I'm a luddite. Telco is the most expensive way to send anything but voice, and there's room for debate even there.)