As others have mentioned I see no saving by buying another new vehicle.1st issue you will take a hit unloading your current truck.
Second the Ecoboost is no economy car fuel mileage will not be a whole lot better than your current truck.
Lastly your Super Duty will deliver a far superior tow vs. the ecoboost. 9500 loaded is pushing the limits of the ecoboost.
Your 9500 loaded trailer puts you in large truck territory pure and simple. Don't fall into the trap of thinking you can tow a 9500 lb trailer with a smaller truck. What you gain in daily driving comfort you lose in towing performance when dealing with a 9500 lb trailer.
Yes much like the Tundra the Ecoboost engine is very capable however the rest of the truck is not quite as capable.
If you want to preserve your Super Duty get a econobox beater car for the commute.
Lastly you should not be afraid of your 6.4 past a 100K. If you don't think it will be reliable past 100K than you have a lemon. A modern diesel engine should reliably last 200K. My current daily driver Duramax has 158K and is still going strong. I drive it as a work truck during the week and it tows my fiver on the weekends.
