I owned a D-Max for two years when the previous generation was launched and never had any issues with it. Two of my friends bought theirs around the same time, and even after 5–6 years of use, they haven’t faced any problems either. One of them has driven his for over 200,000 km.
That said, do keep in mind that support is quite limited. Back then, there was only one person at Isuzu in Karachi who really knew the truck well, so in case of an issue, especially something like an accident, you might not find much help or expertise available. The workshop itself was very basic and quite disappointing, it looked more like a small oil-change garage than an authorized service center