Hi, OP and forum!
I am new posting, but I have been checking the forum out for various reasons over the last 2+ months/3500 miles since I bought my used 2016 XLT EL with tow package, nav. leather... Lots of good information to be found in these forums and lots of people willing to help.
As to your question, I recently had installed the ReadyLift 3/2 (part 69-2070) that was posted earlier with some aftermarket wheels and ~35 inch tires. My setup includes:
ReadyLift 69-2070
Yokohama Geolandar G015 - 285/75-18
XD Series XD820 Grenade 18"
After about 1000 miles on the setup...
Everything fits great, with only a slight rub at 3/4+ turn on the steering wheel. I bought my truck used and the alignment was already off, but you will most likely need a 4 wheel alignment after the install. Mine drove great afterward.
The strut spacers make the suspension feel a little stiffer, but I don't have a problem with that... it handles just fine.
The larger tires slightly affect the acceleration, but once the truck gets going, it's smooth sailing. MPG did take a significant hit, though, dropping about 15% for me (~16.5 down to ~14, good mix of city/hwy, but also lots of idling). Road noise is non-existent as of now, but many things I have read indicate that all A/T tires will start to get at least a little noisy as you approach half-tread life.
Speedometer doesn't seem to be affected as much as I thought... a ~10% increase in tire circumference should mean a ~10% increase in actual speed as compared to what you see on the speedo, but I have seen only about a 6-7% increase.
I am on paved roads 95% of the year (3 or 4 days, 5 or 6 times a year, either in the snow or in the woods). I justify my setup to "the boss" by that 5%. I really just like the look of it...
I will post some pics later this evening. Stay tuned.
edit:
The wheels are not compatible with stock lug nuts. I had to purchase slim 19 mm lug nuts to mount the wheels on the truck.