In my experience (FL1 TD4), the engine/gearbox are solid, the peripherals, especially electrical, are pants. Central locking, windows/sunroof fail on most of these. My wiper linkage failed as well, along with prop shaft bearings. So far (125000 miles) the VCU and IRD are fine. Fuel consumption was around 32mpg but dropped when I fitted Insa Turbo a/t tyres. With the chunky tyres it will go most places, never had a problem when others were spinning wheels.
If if you get a good one you'll be ok. If you don't, almost everything that goes wrong costs £300!