I've had a 2010 6-speed manual for 5 years and 25,000 miles(43,000miles on vehicle). My sister had a 2010 CVT and she is a very conservative driver, the transmission went out at 60,000miles and was replaced under warranty. My car is very low mileage so may not be much help, but I've had no issues with the car at all.
The whole 10 year 100,000mile powertrain warranty was to avoid bad press on the eventual recalls and class action lawsuits that would have followed suit if they hadn't done that preventative measure. If they hadn't done this they would be in the same boat as Ford is right now with their garbage DCT on the Fiesta and Focus.