I've mentioned this on similar threads:
We have a Disco II, but my wife was diagnosed with degenerative disc disease in her back at a young age, so the solid axles on washboard roads really take the fun out of off-roading. So I went against my religion and decided to try out the IFS/IRS combo of the modern rovers. We tested a 2011 RR non-supercharged, a RR Sport, and an LR4, all on the $tealership's off-road course and on the highway.
The skinny:
Range Rover Sport: Most car-like of the bunch. I loved the looks, my wife hated the seats, they hurt her back the most. Definitely sports-car seats. It was out for us because of that, but I loved the interior, although it was much smaller (especially cargo wise).
LR4: Nice quiet drive, exhibited some body rolls on the highway (no big deal), was extremely comfortable off road. Most "Safari-like" of the three, and it's aftermarket support advantage is already noted. My wife would have loved this vehicle had the salesman not had her drive the L322 first...
Range Rover L322: Good Crap, is this how the other-side (rich) live? Interior was night and day above the LR4 and RRS, the highway manners resembled my old V8 BMW 540i more than any SUV, it defied physics and hugged corners it shouldn't be able to hug. Off-road it there is no other way to put it than a member of another forum put: "It coddles your butt like no other" or something like that. Simply amazing. It even out-articulated the LR4, seats were comfier, and felt the best on my wife's back during all the tests.
Aftermarket will be an issue for us (should we get one, we are still a few years out), but the RR is simply in another league. No other vehicle is like it. Others might be more utilitarian, others more luxurious, but I don't think there is anything that really compares for an all-in-one package.
In short, if you don't need the capacity/7-seats of the LR4, go Range Rover.