I also own the diesel. Coming up to 3 years and 55,000km. No problems and a great car -- very glad I purchased.
I swapped out the original tyres at 1000km (also to Geolander AT GO12), but that's because I also swapped out the original rims for a set of Trailhawk rims at the same time. The GO12s have been a great tyre and still have plenty of tread remaining, although it's a little uneven as I've been lax with wheel alignments.
If the chips on your rims are too much to bear, I still have the set of original rims sitting in my garage and willing to sell for a reasonable price. Virtually brand new...