After having towed with my 02 V-10 Excursion and 9300lb TT in the mountains I ca tell you I have never wished I had a diesel. Plenty of power to tow at speed up a decent grade that had other vehicles at 40-45 with the 4 ways on. I’ll take simplicity over complexity any day. I just feel that making it to my destination is much better than stranded on the side of the road because I ran out of Def or I picked up a droplet of water and trashed a $10k fuel system.
Gas is the only way to go for me......and yes I’m a certified diesel tech!