I really like that the you can tell the software how many buttons you want per screen and make them bigger or smaller depending on the child's need. You can also add any vocabulary you like since the software uses text to speech to pronounce the word. You just type it in and Proloquo2Go knows how to say it.
However, the text to speech may be the biggest turn-off for some users. The voices are pretty customizable, but they're not quite human. If that's a concern for you, this may not be the direction you want to go.
The computer voice didn't bother me much and the fact that the software works on sleek, light Apple hardware far outweighs any negatives I saw. The biggest issue we're fighting with Whitney now is that she uses the software as a toy instead of really trying to communicate. I think it's going to take some serious work to get her past that. But we're willing to give it a shot.
Above is a short video of Whitney talking about foods using Proloquo2Go. She's mastered navigation within the software after just a few hours of practice. I'm pleased with how confident she's getting.