I recently bought the Vio. I fell in love with it the first day. It's easy to use and easy to carry around. I really like the tracking feature on my smartphone.
More important, my wife loves it. She no longer worries about me when I'm out drinking with clients and prospects. I now text her my BAC. If it's at an acceptable level I tell her I'm on my way home. If it isn't I stop drinking and go grab some food and water. When my BAC goes back down I let her know when I'm heading home.
Your product is both a life and a marriage saver!