For me it all came down to few things things
Price
To get what I wanted in a version of the new 5th gen would have cost me 12k (CAN) more than what I got my 5.7l Warlock for, and that was just to big of a margin.
Version
1st version of a new truck of a new anything is a gamble, the 4th gen is in its...10th 11th year? They have solved almost all issues by this point (or are pretty close)
Upgrades
You can do just about anything to a 4th gen and the aftermarket availability is amazing, the 5th get will get there eventually but it will take a while
Looks
To get a good looking 5th gen you into the higher end models, rebel, sport, larime, etc....the base models have the ****tly looking fronts IMHO, the sport looks good but the Rebel looks the best to me, but then to get that look it comes back to money
Give it a few years, once they sort some of the issues and get the eco eco diesel in it (and make sure it is sorted) and stop pricing it at a premium i will probably trade in for a 2025 crew crab Rebel with an eco diesel.
I spoke with a dealer and he said the 5th gens are at a premium, they all know it and he said it for 2 reason, it makes it easier to sell a classic 4th gen which they still have a **** ton off, and the 'have to be the first and have it now' people will get the 5th gens and pay the premium.
The 5th gen has some appealing features no doubt, my buddy got one the day after I got my Warlock...but the differences were cooled leather seats, 121 liter tank, 3:92 with lsd, push button start and a winch...all that for almost 20k more...my math says I can get all that installed on my warlock (minus the cooled leather seats) for 4 to 5k...so he paid 15k more for what exactly...flat rear floor, rear seats that incline slightly with more leg room? Not something i was going to shell out 15k for (oh and he has telescoping steering....that did bug me a bit....I would like that)