Well, everyone has their own opinion and preferences when it comes to suspension tuning and power output. All based on one's own experience with past vehicles (what they are used to, or expectations) and what the primary use of the vehicle will be.
I have to say, I too had lusted after the new 6.4L in the '14s. But, I am completely happy with the 5.7L. On the "down" side, it does lack a little Torque down in the lower RPMs. But, when revving along, it does nicely. You just have to get used to the sound of it spinning along for extended periods when under a heavy load. But, it is perfectly happy pulling the higher RPMs for extended periods, whether it be running in the dunes in 4HI or towing up grades. Plus, the 5.7 has been around long enough now that all the bugs are worked out. No oil leaks and a wide variety of available parts anywhere you go. Plus, no annoying MDS. In addition, one negative that can be seen as a positive, is that a 5.7 with the lower power ratings than the Cummins or 6.4 is that it should last longer, as all the components are now "under stressed" and never exposed to extreme torque values.
On the down side, the added low end torque of the 6.4 would give more of a "Truck Motor" feel to it, as it would just pull around at lower RPMs. Then again, it has MDS. That can be good, as it allows it to get the same MPG as the 5.7, but then you have to live with the cylinders cutting out at part throttle and light load, that drives some people crazy. Others don't seem to notice it. Then there have been a few cases pop up here recently where the 6.4 has either leaked or completely failed at the Oil Filter / Cooler / Engine Block assembly, causing major frustration with a big mess and inconvenience.
As far as the suspension, again it is a personal thing. I LOVE it bone stock and praise the build team for putting together a package that rides so firm and controlled on the road, yet delivers 3/4 ton weight carrying capacity, durability when towing or hauling, and at the same time being so flexible and capable off highway.
It strikes a perfect balance for me, and personally, I would not touch it. The high speed ride off road or going through whoops can be a bit soft, but it is is a 6k lbs truck. It's ride is much more firm, controlled and less prone to bouncing / bottoming out than my 1500 is under the same conditions. I prefer the soft ride, and air down and just reduce my speeds.
I think that is what really sets the Ford Raptor apart from the Power Wagon. The Raptor is geared towards flash and high speed playing in a half ton platform, while the Power Wagon works more like a plush Truck, geared more on the side of hauling, crawling and slower more technical trail work.
With the Winch, Lockers and Electronic disconnect on the Sway Bar, the biggest hassle I have is just adjusting tire pressures for whatever conditions I may be running in.
I have ZERO complaints. It does it all for me, and I love it. Towing, Off Roading, Long high speed freeway trips, to just running around town.
Grab one. You won't be disappointed.
Personally, I would rather slow a bit through some big whoops or rocky sections and enjoy a plush ride the other 75% of the time I drive the truck on the highway, than enduring the bucking, tail kicking and bouncing my head off the headliner on every freeway expansion joint, just to hammer over stuff or never touch the bumpstops. My older trucks did that, and I simply could not live with that rock hard ride. It was miserable.
Just my opinion. Everyone has their own expectations, needs and preferences in set up.