I'm a die-hard solid axle guy, but due to my wife's back we started looking into LR4s and RR L322s. I went to the $tealership because they actually have an off-road course (I didn't care about freeway driving so much).
This much is certain, the L322 has superior "technology" right out of the gate. On the highway it hunkers down and reminds me of my old BMW 540i with sport package, it seems to defy the laws of physics. Amazing something so heavy can handle so well.
Then you get it into off-road mode and if-equipped the camera system is awesome (exterior cameras that show all of your approach angles, etc. No more seeing obstacles blind. The articulation blows the LR4, Range Rover Sport, and likely the LR3 out of the water. The suspension is just "better." No contest, at least compared to the same obstacles on the course. Comfort was better also. I was blown away. You can still get the $200 sensor-lift and use compautomotive 18" wheels on NON-supercharged models through 2011 (and there is some thought the 18's will mount on Non-SC 2011+, but no-one has verified yet, still too new for owners to venture off-road).
Now, the LR4 was 90% of the RR, but with better cargo/passenger hauling. It exhibited much more body roll on the highway and off-road it would frequently lift a tire in the air on off-camper portions of the $tealership course while the RR was always firmly planted. I would have no problem getting an LR4 (or LR3 in your case), because I believe the aftermarket support is an advantage over the loss of articulation. L322s have little-to-no aftermarket support, and it even seems like this site's owners have abandoned their ExPo/Overland Journal L322 Rig.
The Range Rover Sports was essentially an LR4 with the on-road performance of the RR at the expense of some ground clearance. Was it Chris B. who built up a RRS for Expedition Portal? The thread is here, and it details what to expect to get the most out of it. I wanted the RRS, but out of the 3 vehicles it was by far the worst on my wife's back thanks to the hard sport seats and the sport suspension. It hunkered down on the highway pretty well, but off-road it suffered the same lack of articulation the LR4 did (I think they use the same suspension design). You can fit 18" Compautomotives on NON-SC RRS too.
For me, I'd deal with the lack of aftermarket support and go all out on the Range Rover. I was blown away by its capabilities. I have no doubt that with a 2" lift and some decent tires the stock Range Rover could tackle some pretty high-end trails down in Moab. Granted, you may need to take some bypasses because the wheelbase and IFS/IRS combo isn't exactly ideal for rock crawling, but when you consider how well it does on-road coupled with how well it handles off-road, it is a pretty formidable rig that desperately needs to ditch its 20" rims get out of Mall Parking lots!