Mitsubishi only advantage is the 4x4 mode seems more famous/durable as they race a lot in Dakar race with their 4x4 technology.

Hailat really a let down nowadays, if not because of Toyota brand i think it is worse in the lot (Besides from reliable, everything from comfort to safety features is not the best), Dmax at least the 1.9L engine really fuel efficient, but not really powerful. In Japan, Isuzu is famous for making small diesel engine for trucks & pick-up. 

Pickup Brands famous for

Mitsubishi - 4x4
Toyota - Reliable
Isuzu - Fuel efficient
Mazda - Another rebadge Isuzu
Nissan - independent rear suspension system

If base on today market with high diesel price, 1st choice would be Isuzu D-Max.
Wait for new Isuzu D-Max with new 2.2 DDi MaxForce engine.

Their on-road comfort is good and i have seated in 1 before (2nd Generation, 3.0T) in the rear seats from Kulim to Kuantan without any discomfort along the way.

Front seats most pick-up also quite similar, the rear seats are the one more important to know if it is comfort or not.
Pick up family members seat behind and listen to their feedback.