From what I read on another LR forum, the TD6 discovery is being ordered by people that currently own an aging Touareg TDI. I can see where the Discovery is a good choice if coming out of a Touareg. And if you're a fan of diesel, there aren't many options left in the US.
Speaking of Diesels. I'm really happy with my D5 HSE Diesel as is, but there's a company that has a chip for the D5 diesel and it sounds fantastic.They claim 325 HP,776 Nm Torque and 33 mpg? Maybe other folks know this company and have experienced their chips. Tempting Mod
https://www.chipexpress.com/products/land-rover/discovery/diesel-chip-tuning-boxes/5609/