Short: Pretty useful in quiet environments (out to eat, in office). Doesn’t handle background noise well when driving but can save pesky typing.
I recommend it.
I use my Android phone to talk, text, e-mail, navigate, and search Google for information about something that has come up in a conversation.
Vlingo does a very good job replacing typing in Google searches. It also handled navigation searches pretty well.
Vlingo does a fair job starting texts and getting the wording right. But not good enough that I would send a text it generates without checking it.
And I wouldn’t let Vlingo anywhere near my e-mail, which I need to be accurate, typo and wrong word free.
I like that it has a one button launch (on my phone the searched button pressed long will launch Vlingo).
Examples that worked for me in a nice quiet environment were:
weather in new york city
text devin thursday 1pm
launch angry birds
get directions to Rowdy’s Range
google images christina hendrickson
text paula "how is your trip to NYC going?”
My results varied in a car. In my truck it worked similarly. While riding in a smaller car, with more road noise, it would get it close, but usually miss a word.
All in all, I find it pretty useful and worth installing. I recommend it.