There are always exceptions to trends and you seem to have been lucky, but I can assure you that the D3 and RRS are even worse for reliability than the P38. I have seen the same individual cars in those workshops for different faults month after month, and I saw a clutch change which cost £1500
because of the labour, and that was at a non-franchised dealer where the labour was less than half the price of the franchised places and they found a quicker way of doing it without removing the entire body from the chassis. I have also seen several wishbone failures in the flesh, not just comments or photos on forums like this.
The editor of LRe brought a press fleet D3 on a trip I did around the Alps and it did really well - comfortable, quiet, huge carrying capacity and not a glitch, but you'd expect a brand new vehicle on the press fleet to be reliable. I don't question its comfort or capability - it was very impressive, but official surveys by organisations like the AA (UK version of AAA), its rival the RAC, JD Power and so on all back what I have seen with my own eyes hanging around the workshops with my friend - they are mostly extremely unreliable and hugely expensive to repair or maintain.
I suspect the decrease in warranty claims at the Vegas dealership may be due to the quality of the body and cabin improving, so all the minor and cosmetic faults have disappeared, like rattles, squeaks, rain leaks, central locking, electric window and sunroof problems and the like. Maybe LR are more careful with the assembly of US bound or all export vehicles, but there are serious design flaws in the vehicle from a maintenance view point - they just aren't built with an eye beyond the three year warranty period. Previous vehicles have a bad reputation because of niggling faults rather than major problems and due to so many owners or garages doing shoddy repairs which go wrong again or affect associated systems.
It sounds like you have a good one (someone has to), so don't be tempted to get rid of it to buy a newer one unless it goes wrong or its warranty period is expiring!