For a full picture go to Disco3.co.uk.
Good points, very comfy, great engines, very, very good off road, great load carriers, great long distance travellers.
Bad points, can be expensive to run/maintain (as any car can be if you are unlucky), that is it after 6 years of D3 and 2 years of D4 ownership. My D3 was the longest I had ever kept any car.
For some reason, a lot of owners of other Landies have very negative views, listen to people that have owned one, there are a few of us on here.