I don't quite understand all the technical background, but I can attest to the advantages of high DR in my work. I do a lot of interiours, and most of them are high-contrast situations, often necessitating trips to PS for better noise control (I bought Noiseware Professional which used to be better than LR, maybe still is), occasionally blending in different exposures (I always do bracketed shots for interiour work), etc.
With the d7000 and now the d800, my trips to PS noticeably decreased. In fact, I don't recall any situation in the past year where I had to use blending. My only comparison is the 5D MK II and Rebel T2i, and my gut feeling is that you can push the d7k at least a stop more without image degradation (colour shift, noise, etc.) In Lightroom terms, this is about 30-40 points on the shadows slider, or being able to push both blacks and shadows on the Tone Curve significantly more. For me, it means staying in Lightroom for 99% of my workflow. You can just feel how much more malleable are NEF files then CR files.
I'm not sure any of this matters if you're shooting JPEG. Except maybe if you have ALO enabled. With Canon's, I never used ALO (and I didn't use ADL it with the d7000), but when I bought the d800, I just left ADL (the Nikon equivalent to ALO) on Auto setting. I'm a raw shooter, but lately I've been experimenting with JPEG+RAW because I started shooting events now (not much interiour work lately). As far as I can tell, ADL works well, I don't see any image degradation, and the change is quite subtle actually, but for the better as far as I can tell. Where it truly matters is when you shoot RAW.
I heard a good description of RAW somewhere - RAW is like a box of light. When you look at a RAW shot from either Canon or Nikon you basically see the same image and DR. The difference becomes prevalent when you're start messing with it, changing exposure or using curves. With a high DR camera, you can push shadows more without significant image degradation. It is as simple as that. You have a bigger box of light with a high DR camera
By the way, your photos are magnificent! I don't even know what most of my favourite photographers shoot. I know some shoot Canons, others shoot Nikons - and the end results are all magnificent. Once you have invested in either system, I don't see much reason to change. I didn't have a huge investment (Sigma 10-24 and a Rebel) when I bought the Nikon d7000 (and the new Sigma 8-16 which was to replace the 10-24 anyway). The 5D MK II wasn't mine. For the things I shot back then, the high DR of the d7k did make a difference, made my life easier. But for the things you shoot, it might make zero difference. As I said, what you get with high DR is a bigger box of light, but if you don't see the limits of your current box, then you don't need a high DR camera
And I think for JPEG shooters it doesn't matter at all.