Hi, just wanted to bring my take on this.
After several attempts to charge my Pre2 with cable, either with it's original plug (1A) or even with my Touchpad's (2A) I found that after a fair amount of time (a few hours) my phone would still be far from fully charged, but I'd make it home, placed it on the Touchstone and within 1/2 it would easily be much better charged, most time a full 100%.
So today, I did it again... forgot a Bluetooth active connection to my stereo headset that I was using with my Touchpad, and it drained the battery to 30%.
So I plugged it in and left it on for over ten minutes and when I checked, no change. I expected at least a 1-2 % increase, but nothing.
So I went and grabbed my Touchstone from my car, and plugged it in.
10 minutes and a full 10% increase up to 41% from 31%.
It's been about an hour now and I'm already at 98%.
So either I have a faulty micro-USB connection (I tried multiple cables) on my phone, even though it will eventually charge, and have no trouble to connect to a computer... so I wouldn't believe it to be faulty.
In case someone mentions that it's possibly a "over-powered" Touchstone... I have 3 Touchstones, and it's the same for all of them.
Just to say that I hate and avoid plugging my phone anyways (unless I have to to upload videos/musics) so it's no biggy, but it's still interested for me to see such a huge difference.