Just trying to look at engine choices. Not enthused about plug in hybrids so would probably be D350 or V8 P530. Does nobody buy the V8 anymore- quite like the idea but real world maybe not really get any advantage? Would be grateful for any comments on that engine choice please.

Real world - would you tell the difference? Only at the pump I suspect.
The V8 will sound better and be more refined.
Sure the V8 is quicker but how many of us ever fully rag our cars - when I tried to drive mine like I stole it, I very quickly realised a hedge awaited if I didn't tone it down a bit.
So if MPG doesn't bother you, get the V8.
If sub 20mpg (and probably closer to 10 in traffic) makes your teeth itch - probably better with the diesel.

One thing that confuses me is the difference between the current and previous models.
The L494 is lighter and smaller and yet, with supposedly the identical drivetrain, gets 6+ mpg less.
Realistically, the MPG numbers for my D300MHEV are in the right ballpark so I can't see how a new shape, one could do better.
Either I'm missing something in the tech or they aren't using the same testing regime. 2021 L494 D300MHEV Autobiography
2019 Discovery Sport D180 HSE

Understand from Harry’s Garage the the L461 has the lowest drag coefficient of any Range Rover built - hence the better MPG. Also gearing ratios is different and Inline 6 smoother than older V6. There id also the better MHEV element.