I have no experience with the 2017 F350 Diesel Lariat 4x4, how it handles, or how it tows. I only have experience with the vehicle's I've owned.
I will say, I have tried it both ways on every vehicle I've owned and every trailer I've owned. My truck of choice has always been GM (Chevy Silverado), but I did tow with a Chevy Suburban and we towed our pop-up with a Chevy Lumina Mini-Van for years (Never WD for that set up).
From my experiences, the Suburban HAD to have Weight Distribution. The rear end was just too soft and the end squatted way too much.
Our next vehicle was a gas 3500 Chevy duly. I used the same WD as I had on the Suburban. The trailer was 6K in weight. With the WD it just handled a LOT better.
Next truck was a diesel 3500 duly (Silverado). Bought it used and it was set up with everything ready for towing. By now we had our 31 foot Springdale and I did try towing with and without WD. Although it towed just fine without WD, there were time I would get a squirley feeling, maybe some sway, weird sensations when semi-trucks passed, and seemed to be very bouncy. With the WD, I never experienced that. Same WD system that I used with my Suburban.
Fast forward, brand new truck, 3500 diesel duly (2014 model). With this camper I switched from my original Reese WD to an Equal-i-zer. I didn't hesitate to get the new system with the new camper.
After getting truck, I did attempt to tow without the WD. I only got as far as the end of my driveway and I was ready to put it back on. I've been using it ever since.
My suggestion for the OP. Considering you already have a WD system, why not try towing the trailer with the new truck without using the bars. Then try towing with the bars. See which feel better, handles better, and give you better peace of mind. Then do what you want and skip all the "sage advise" on these forums.
