This thing is an absolute gem. I installed it in my 2006 Civic, and I fortunately have the Aux input jack so I can listen to everything that the Pre does through the car speakers, even talking on the phone as long as the volume in the car isn't too loud as feed back will occur.
Anyway, I have the car charger with the #2,3 shorting method mod done on the charger from bestofferbuy.com, you know, the 1.2Amp charger. I had my GPS running with the text to speech turned off, the Music remix App from Homebrew running a nice set from DJ Faskil, multiple phone calls via bluetooth and also many texts, and some other simple app opening like Trapster, which I am trying to like, but the delay is making it tough.
With all of this going on, the Touchstone still kept the charge increasing at a slow but constant rate. Actually I can't even say it was slow. It increased the battery percentage about 1% every 1-2 minutes. This test was by no means as thorough as I wide like to be performed.
So to sum up, I like touching Touch-type-stones and also black matte finish covers with my person and my hand sensors, leading to what I call one helluva TouchStone accessory. Aww yeah kid. Pea Soup.