My 2017 Discovery 5 HSE Td6 has been rock solid. I lost all of my money on my extended warranty - I've never used it. I now have about 85k miles on it. It was one of the earliest ones delivered in the States.
Mechanically, US / NAS L494 and L462's seem to be consistently well behaved. Early on before OTA updates were applied, the InControl Touch Pro infotainment was buggy, but they have sorted that. You'll see lots of issues overseas with 2.0 4cyl diesels (SD4 and Ingenium 4cyl diesels) so if you look around on forums, make sure you verify which engine a poster is talking about. Those engines were never available here, nor was the SDV6, which was also very reliable over there.
My local shop says the Si6 (supercharged 6cyl gas) was also quite reliable. (EDIT: unless they were modified - there are aftermarket chips and pulleys that can push them well over 450hp).
All LR's of this era (Discovery, RRS, RR) have the ZF 8HP transmission, which is perhaps one of the best auto boxes ever made, and my EAS has also been perfect in spite of my best efforts to break it off-road.