The Range Rover (not the extended wheelbase) is still the king of the crop when it comes to breakover, fording depth, approach, departure, etc. Next to the Jeep Wrangler it's actually the best. It's much better than even the TRD Pro 4Runner.
The biggest downside to the modern rover is:
1) Tires. With 20" rims you are lucky to get off-road traction, let alone actual sidewall strength that a D or E-rated tire offers. If you could fit 18's on the newer rovers, things open up.
2) Body design. The engineering is solid, the body sucks. Adding winches and armor is next to impossible. I know with the LR3 and 4 stuff is available, but hopefully you can get it for the D5? With my L322 you can't get sliders to save your life. Without sliders and armor your are essentially stuck with an expensive rig that is the "best in class" for 4/10 rated trails and that's it. Maybe some "soft" 5s if you are a good driver. Modability is nil. It's dumb. This is where the 4-runner will blow you away. Put on an OME 3.5" lift, put 33" tires on it and toss on ARB-lockers and you've just out-classed the Range Rover.
There is so much potential in the modern platforms (cross-linked air, etc), even the reduced weight of the new rovers vs. the previous generation rovers is incredible. But it is all wrapped up in a bubbly body design. The SVX team even had to mount the winch on the REAR of the Disco 5 because they couldn't mod it to be on the front. Really? For $100k+ and you can't mount a winch up front?
Oh, and speaking of the discovery 5, the radiators are in front of the WHEELS!! Even if you could get an aftermarket bumper, it'd expose the radiators to damage. Talk about dumb. That's the price to pay for the bubble "Ford Explorer" facisa (that is designed for FWD cars by the way), is there isn't any room for a radiator in the traditional spot, so they put it in front of the tires! That's just trail damage waiting to happen. So I really love the D5, but I can't recommend it. The first photo of one on safari in Africa (Overland Journal) showed the plastic underside all tore up.
So really, your best bet is an LR3 or 4 if you want to enjoy a modern rover on the trail.