Based on what I've seen so far of the new JL platform, I don't have high expectations for the Gladiator. FCA's quality control just isn't where it needs to be with some of their vehicles. But of course until their sales #'s start to suffer, that's not going to change.
GM's gasoline engine has actually gotten some criticism as being rough-running, especially on 87 octane....whether that is an indicator of the engine's longevity/reliability or just an inconsequential quirk is anyone's guess and will be proven over time. The 2.8l diesel isn't GM's design (despite what the Duramax crowd likes to claim), though it actually has a bit of a track record in overseas vehicles, to include the Jeep. So long as the emissions are fine-tuned, i don't see any potential pitfalls with that design.
Ford's introduction of a turbo-gasoline may in fact shake up the midsized market, and motivate other OEM's (Toyota) to put out more torque-friendly designs....we'll have to wait and see.
I've looked at the chassis' that the two OEM's (Ford and Toyota); Toyota seems to over-engineer their 1/2 ton in a number of measurable ways....I therefore draw the conclusion that Toyota's truck is more robustly built, but I definitely acknowledge that conclusion is totally subjective. The differences in brake size, gearing, frame, drivetrain specs aren't subjective however, and are well worth a look.
