I have been using my Tornado for over a month now.  It has held up great and I absolutely love it.  Matter of fact, I just received my second one today.   
I agree about the USB fast charger.  It is well worth the money. The stock 510 chargers work fine, but take quite a long time.  The USB charger cuts the time in half.  
The Tornado is the best purchase I have made, with the exception of buying my first Joye 510 kit from Cignot!
Ken