We love our Mega. Wish it was a dually. Your 08' should have the better gearing in the manual. I'm running DDP injectors and a Smarty. Hopefully your commute gives the engine time to warm up and avoid Regen. My boss has an 08' Ford 6.4l. It's mostly used for short trips with occasional toy hauler duties. The truck goes into Regen daily. 12mpg. When new it averaged 15mpg. Yes, I did try to talk him into Mega/Cummins.
Did yours come with the Ebrake enabled? The Mega's GCWR should help the overheat problems you were having with the 2nd Gen. I did add a rear sway bar and airbags to assist with the onboard camper. Not sure if your gooseneck/camper combo will need it. Might be ok stock or with the Torklift Stable loads.
93' YJ w/factory hood