Anecdotally you may find that there is a gulf between the Dii and D3/D4 platform in terms of reliability. The reputation earned by Land Rover for reliability was on full display with the Dii (and P38), particularly as that engine block really went past its years of good machining.
The D3/D4 platform is a completely different beast. In terms of reliability, it's head and shoulders better-there are things you'll need to account for because it is essentially a laptop with wheels but once that is accepted they can be superb trucks for your application.
This.
We get a LOT of insight into the problems people have with their LR's - not just electronics/diagnostics btw. Here are a couple of take-aways:
1. Mechanically, modern vehicles (not just LRs) are miles superior to their 20+ year old brethren. Comparing an axle replacement on a live-axle vehicle to an axle replacement on a modern LR is not really a good comparison (sorry TeriAnn...). Catastrophic axle failure on a newer LR is a rarer occurrence whereas axles were used more or less as mechanical fuses on older LRs. Older LR owners usually carry an axle or 2 as a spare if traveling to remote areas.
2. LR was... adventurous in the use of electronics in the 90's and BMW (who were always incredibly adventurous in this regard) didn't help. Ford fixed a lot when they took over, and from the Ford-generation vehicles on (ca. MY 2006 / AJV8 L322, Sport, LR3, LR4...) LRs became much more reliable.But even early L322s are light-years better than the P38... And the D2...
3. All more modern LRs are relatively reliable in that they will not often leave you stranded - but they may cause you to consider drinking heavily when it comes to ancillaries / sub-systems. And going to LR dealers to have these items repaired will cause even wealthy individuals to take up drinking. Find a good indy when you're out of warranty.
If you are a DIYer or plan on self-sufficiency for remote travels, you will need a diagnostic tool and some additional skills. Not hard in this day and age, tho. No more difficult than learning how a carburetor or diesel injection pump worked back in the day.
I drive my LRs with an utter minimum of service - not by design but because I have notoriously bad luck with any repair shops regardless if indy or dealer and because I don't have the time to do everything the way I'd like. Even my P38 was remarkably reliable for that (aside from heater stepper motors, door locks/BECM issues, and millions of other minor problems). In 25+ years of LR DD I've had only one issue where I needed a tow (knocking on wood) .