Morning, not posted before so hello! Normally drive a P38 but I also have a Freelander as a backup vehicle (not helpful if you're after a diesel, but it's petrol: got a bit sick of headgaskets so drilled a couple of holes in the thermostat - never managed to get quite so attached to it as I have with the Range Rovers and it's cured the cooling issues, think the coolant capacity's a bit inadequate for the engine possibly).
(Engine aside, and won't be the same problems with a diesel). It's actually a surprisingly useful little car. As has been said, the viscous coupling can go, but it really isn't an enormous problem to do it. Something that also fell apart on mine was the IRD (probably due to the VC failure? - was a cheap layby purchase with no history attached), but again, it wasn't overly expensive to sort out.
Overall fairly capable and actually not a bad car to drive around in. Apart from the diff and cooling it's just got a bit of a battery drain problem going on. Nothing too bad (my GEMS P38 was eating a full battery in two days at one point, the Bosch I use for work never seems to lose charge at all, Freelander's between the two. Need to look at it when I have the time, otherwise it seems happy with a maintenance charger on it for now).
Personally I actually quite like them. Used a TD4 semi-regularly on a farm for a while a few years back, and my spare one's not bad for a car that gets little use currently, and thus misses out on the daily maintenance and fixes it'd get from regular driving.
People I know who have, or have had, TD4's have not had strings of problems with them, think the weak engine's probably just the 1.8 petrol, the two Freelanders I've used fairly often have been OK overall.
P-Reg HSE (1997 model year).