Since you seem to be concentrating on engines, the 6.4L engine is still largely
unproven. The DMAX is
totally proven. On another website I belong to, there's a member with a DMAX that makes 1,000 rear wheel HP. No Ford diesel, not a 7.3L, 6L or 6.4L has come close to that.
An Allison 1000 series transmission is a
true medium duty 6 speed transmission used in larger medium duty applications (like Ford F-650's)than the Ford torqshift 5 speed transmisson. It also has a manual shift feature not found on the torqshift.
Did you ever ask yourself why Ford uses a very similar Allison transmission in their Ford medium duty trucks, like the F-650, but they don't use their own in-house Torqshift in the F-650? If the Torqshift is so tough, like an Allison, I wonder why they don't use them??????
The 11.5" rear axle in the GM is much stouter than the Ford 10.5" l/s rear. It also locks quicker and stays locked
Now the last time I drove a truck, the main thing that drives it is the
engine, transmission and rear axle....... they're the heart & soul of a truck. Nice to have 5 REAL proportional gauges instead of idiot-light gauges to monitor that heart & soul, too. That's where I want my money-in the components that take the abuse whenever the truck is running -not a front axle that rarely sees any service.
IMO, Ford's advantages help a much lower percentage of their owners- like snow plowers, hard core off-roaders, guys who need more front axle. That's where Ford has the edge. I'd say 90% of the guys who own Ford & GM trucks barely ever engage them in 4x4 not to mention plow snow or go hard core off roading. Also you have to realize there's a lot of 4x2 trucks out there making the Ford advantage in the front end even less significant.
Let's face it, most diesel truck 4x4 guys don't even need a truck, not to mention a diesel 4x4. For a lot of guys, it's just a lack of masculinity compensation issue. I really need a diesel 4x4 pickup. I use it to tow and carry lots of tools & lumber for a construction business, not tow a 1,500lb Cub Cadet lawn mower or look cute.
Like you said, we're off topic, so let's just say buy what makes the most sense for you......'nuff said.