If yours was a higher end trim level 2006, it should have been worth more than $10k having only 80k miles on it. Even if it was a higher trim package, there are a lot more options available on the lower trim models than was even available in 2006. A $50k model 2016/17 is going to be a top tier trim and have bells and whistles that weren't even thought of in 2006 along with pretty drastic capability/performance increases. To call anything from 2006 "comparable" to a new $50k truck isn't really reality. A 'nicely equipped' 2016 XLT off the lot for $36k will even have things that were only top tier options in 2006.
The base engine in 2006 was a 4.2L V6 with 202HP and 260ft/lbs of torque.
Your 5.4L V8 put out 300HP and 365ft/lbs of torque.
The base engine in 2016 is a 3.5L V6 with 282HP and 253ft/lbs of torque.
The 5.0L option for the 2016 has 385HP and 387ft/lbs of torque.
Anything the trucks of yesteryear could do, the trucks of today can too. Those worried about handling a load, don't need to be. The 700lbs weight savings they talk about really doesn't put it into perspective for me. The best comparative example I've seen says the heaviest, largest, most feature laden 2015+ is 200lbs heavier than the lightest, smallest, most basic 2014 that was built. That 700lbs wasn't much. Then take into consideration the lower center of gravity from the lighter body work, changes in frame design, setting the engines down farther between the frame rails, all this leads to extra stability.
After having over 28000 miles under my butt in mine, I'm still impressed by all of the innovations of the past 10 years, as well as the thought that went into most of the implementations of those innovations. I came from a 2006 Ford Ranger XLT that I paid just under $20k for when new, into a 2015 F150 Lariat that I paid less than $40k for, also new.