I love my '11. My research hasn't shown any chronic problems in the '11 compared to the '12-14. It tows really well, and gets good mpg when not towing. So nice and easy with the low torque curve. I couldn't be much happier with the truck so far.
I wouldn't worry too much about your friend's concern about longevity. Yes, the EB goes against old school thinking about displacement and all of that. But this isn't an off-the-line V6 that they found in the warehouse and bolted a turbo to. The engine was engineered from the ground up to run the power and pressures it deals with.