After spending a bunch of time in both trucks, I felt that this thread was only a matter of time as there is a lot of hubbub about which one is better. Here's how I rate them, with which vehicle is better in each category:
Engine: LR4 (5 liter). They say that there isn't much of a power difference, but acceleration and response feel much stronger in the 5.0.
Cameras: D5, when they work. Greater clarity and smoother-not a choppy 25-ish frames per second like in the LR4
Radio: LR4, The Harman/Kardon system has better imaging, clarity, the soundstage is farther forward, and the low end detail makes it clearly the winner. I tested this with my critical listening CD I use when testing high-end audio equipment (My other PITA hobby). The D5 radio/source interface is better, and station selection is instantaneous.. In the end it boils down to sound quality, and no matter how I adjusted the Meridian sound system everything below 500hz starts getting muddy..
Informant System: D5, It's faster, higher resolution, intuitive. Navigation is really nice with the bigger screen, and tracks your movement smoothly. You still experience some delays with it, but all in all it is the best..
Visibility: LR4, the D5 windscreen is a softer angle and the doors are higher. If you are on a rough/offroad trail, low windows allow you to lean out and see where your tires are going to attack, if you are going to miss that rock, or if you are about to lodge a stump in the side of your door. The D5 door doesn't appear to be designed with this in mind, despite all the off-road capability talk..
Lighting: Headlights: D5 by a hair.. Really bright and wide on both trucks, but the color of the Xenons on the D5 seem to bring out more detail.
Interior: D5 hands down. Very luxury car-ish, cool LED backlighting under the seats, dash and other features
Ride: LR4, but this is
truly a matter of taste. Both vehicles ride very well and take road bumps softly, but firmly. One big thing to note: Driver position seems to be very different in these cars.. In the LR4 I feel much more upright (but comfortable) as if I am in an offroad vehicle, but in the D5 I am more reclined as if I was in a sedan. The D5 is much lighter, and you can feel it in the turns.
Interior: Tie: The fit and finish is nearly the same on both vehicles, but this again is an apples to oranges comparison.. The LR4 speaks to Luxury/Utility, and the D5 is geared for Luxury/Contemporary. The D5 matte dash and interior material (almost suede-ish) is prone to stains, I got pizza grease on the interior armrest on the door and after 20 minutes of scrubbing it still isn't completely out.. If you buy a D5, you can throw away your Armor-all: everything is piano gloss or matte in there. D5 is Lexus-quiet at 85mph.
Appearance: ...Annnd here we go again. I will say this, if you are buying a truck to get noticed/compliments/nods, the LR4 wears the crown. The D5 does a better job of disappearing into the crowd- I drove the first 1000 miles without a single glance from both the general public and LR/RR drivers alike. But after the first week or so, the damn thing starts growing on you in the fact that it
is a really nice truck, but is
such a departure from tradition.. In Far East markets (the ones that are growing the fastest for JLR) that favor the sleek, high tech look, this could be a game changer for sales. It may be ******* off us traditionalists, but "De gustibus non est disputandum", fellas.
Overall: If you put both trucks in front of me and said "Pick one", I'd drive away in the LR4. This is due to the LR4 looking, driving,
and feeling more purpose-built, which is what I got into this game for. The LR4 does an excellent, excellent job of melding high-end quality and off road capability. The D5 is a dichotomy: It looks and feels like a high-tech luxury SUV, but in reality it can damn near drive over a steel picnic table.
The LR4 says "Let's do this". The D5 says "No doubt I can do this, but don't you dare mess up this interior with those muddy boots".
Off Soapbox. Now you can all go Google "De gustibus non est disputandum"
Mike