Land rovers are notoriously unreliable. I've had experience with three of the old model Range Rovers over 6 years and one of the new style (while still under BMW) Range Rovers. All of them had problems....as in service stop every few months.
They are great performance-wise though, my brother went off roading all the time with them and never had a complaint about their performance in that regard. Especially with the new engine's even when on-road they can definitely still throw you into the back of your seat.