Reliability is what you make of it. Do you take care of it and do you fix issues as they come up. For that matter did the previous owner/owners.
My first Disco 1997 I had for 12 years before the frame rotted out (my fault I didn't wash it like I should have) but as far as real maintenance, I had very little in the 12 years I owned it. Lots of add on and upgrade expenses. But other than oil changes and a fuel pump I didn't spend more than $1000 in the 12 years and 60k miles.
My Second Disco a 2002, I had for 3 years and spent around $1200 in repairs and about that or more in upgrades. I only put 4k on it in 3 years. My biggest expense was head gasket.
The 2003 biggest known issue is oil pump...but this should already be taken care of by now.
Now keep in mind my wife had a Honda Minivan that cost more than both rovers combined in repairs and around same mileage.
So reliability can go either way.