Also very happy with mine, 2020 Lariat 4wd 145 in wheel base, 3.73 rear end. It is still new; 5k miles and almost exactly 20 mpg (hand calculated). This is all light city driving, 1/2 of it in the (Alaska) winter, all with the start-stop disabled. I drive with a light foot and the truck is generally empty, but for almost no highway miles I am pleased. I'm sure gently highway drivers (keeping it at 65 mph) would average 24. My transmission is smooth, but I do notice a bit of "put-put" during start up idle. I had the TSB for white smoke addressed (turbo oil supply line) but what feels like a gentle missfire remains. I could not find evidence of missfire on Forscan. I don't fear the timing change or VVT system, I change the oil frequently and believe the engine/transmission will outlast the rest of the truck. I drove a 2005 Ford Focus for 15 years, I see no reason why this truck should not last 20 years.
Where is the coolant leak you are experiencing? I'll be on the lookout. Thanks for mentioning the lubeguard; good to know.