I had a 2008 Landcruiser 200. Loved it. Like a lot of early 200's it had oil use problems and a steering rack failed. Toyota fixed both without blinking. It did let dust in the rear, but like most instances, this turns out to be where ARB forgot to seal the wiring inlet.
I really wanted to buy a disco as a replacement. On paper it is a better vehicle. Enough power, better economy, great built in suspension lift / drop, slightly better payload, more boxy shape etc. Tata even seems to have fixed reliability somewhat. But the more I looked into it, the less convinced I was.
Owners on these forums say they have been reliable, great. But talk to many owners, check review sites, look at Edmunds and other reliability sites and a few reviews. I know the internet is not always the best source, but there is overwhelming evidence that the problems still exist IN MY VIEW. I have 4 friends that had Disco 3's 4's or recent Rangies that voewed never again. Constant returns and fights with the dealers who say 'no fault found' or 'never seen that before'. The best one was the faulty handbrake on my mates Disco 3. It kept locking on, after several returns to LR, he googled it. The internet was riddled with the issue - like a plague. He showed that to LR and they instantly fixed it and admitted it was a common problem.
On top of that, all the dealers are in capital cities or on the east coast. The one exception is Alice Springs. There is 1500 km between dealers in the middle of Australia. One friend proudly said no problem, LR will arrange towing to a dealer. But when he read the fine print, there was a 200km limit then x$ per km with no off road service. WTF?
Anyway, despite the Disco 4 being a theroetical better vehicle, I could not convince myself that I could rely on it for touring.
I have a new 200. Love it. They fixed the economy a little too.
I suggest you join Lcool for the 200 and Alruo (?) for the disco to get more owners opinions.