Yep I have taken my D3 on tracks like that and more regularly. And I can attest as a witness that Terry and some of the other crazies on here take their Discos on some tracks MUCH worse than that I was too chicken to try.
D4 or 110. Great question - loved my 110 and had that for 7 years. Put it places it really shouldn't have gone and felt comfortable doing it. Now I have gotten old and enjoy lattes the D4 still goes the same places - now I will qualify that I haven't and won't put it some places but that's due to the "niceness" of the car. It's handled tracks easier than the 110 did and by tracks I mean things similar to Mick_Marsh's photo.
For comfort and ease of driving - D4
For the hard throw at type and ruggedness - then go a fender...
But I would take either over many others.
The Disco do with class what the fender does to a level when the fender steps out on its own with sheer ruggedness.
Slightly off topic...
This is interesting,a wheel sensor was playing up on the Defender a while back and therefore the Traction Control/ABS was disabled at times.
My son had it on Fraser island.He found the capability of the vehicle dropped off considerably,when TC was not operational.
Whether this was because of his driving style, as the vehicle was not how he was used to it,is debatable.
Apart from the character vs luxury debate, the big difference between Defenders and Disco's is long term ruggedness and chassis strength.
If you go bush occasionally buy a Disco. If you go bush all the time get a Defender.
Or, if you have 90K to spend, buy two Defenders. A low km newish one for $55K for the future and an older one for bush work now for $25K. You will have $10K left over for accesories, rego, insurance, servicing. Both will hold their value much better than a new Disco and you will have more fun IMO.
Defender for $90K? It's a limited edition and too expensive.
Is the D4 monocoque?
No.
The T5 Disco 3 / 4 and RRS have the strongest chassis LR have ever built. The strongest CV joints. And the strongest axles. People often confuse "ruggedness" with "reliability", and "reliability" with "enough knowledge to repair".
From new, I took my D3 through tracks far worse than any shown here (LandAndy can attest to that). Pinstriping was never a hindrance. Neither the occasional dent. As I used to say - if I wasn't going to use it, I'd buy a Jaguar. Same went for the L320 Sport - which won the W4 Challenge 2014 and was runner-up 2015 (to a Range Rover) ahead of a plethora of modified Deefers. Same goes for our D4, and now our L494 Sport.
If you're willing to use it the way it was meant, a D4 will run rings around a Defender off-road. "Are you willing" is really the issue. And if you're of the opinion a Defender is better in sand, then you're either not preparing correctly, or your approach to off-road driving needs to be modified (this would be a great time to plug my 2-day sand course for Terrain Response vehicles, but I'll show restraint and put it in a more appropriate thread).
A 110 Defender is cheaper, easier for the traditional mechanic to repair, and easier to load up and clean out. But it's not a better off-roader.
Cheers
Gordon