I don't have either one of these two choice in my truck. I did test drive a truck with both twice. While the 12" screen looks really cool, I found it to be distracting when driving and making cabin adjustments. I had to take my eyes off the road and look for the touch points on the screen. I like the knobs in combination with the 8.4 screen.
I didn't choose e-torque because I don't have to deal with a lot of heavy stop and go traffic, while I tow a boat and sometimes a small enclosed trailer, the 3.92 is plenty adequate for my purposes. The 3.21 would suffice just as well for me, I just prefer the "grunt" of the truck to be on the low end. No regrets with the 3.92 for me. My other reason for not going the e-torque route was when the battery pack has to be replaced, or repairs out of warranty, what is the cost, and what have you really saved in real dollars if you are a long term owner? Enough to offset the cost of gas saved, jury is still out on that one, but I've got my doubts. I've experienced stop and start in rental cars - I don't like it end of story.
The only time this truck let me down was when the 3rd brake light started to leak this spring. Got the gasket replaced and has been dry since, hope it stays that way. I've never understood why an engineer would punch a hole in a perfectly good piece of metal up on top and then expect it not to leak. You would think they would know better than that, all of us out here get it.
