Hi Dennis,
I'm a shift-lens junkie, especially for panos. For years, I've had a 35pc then got an 85 t&s when I was shooting film before getting a 28pc for the DX.
They are great for doing panos since the images match almost perfectly and that is the main reason I still use them today. I also se them to increase image resolution by overlapping images and using them for an extensive architecture project that I'm working on.
With a Dx camera, the widest available lens is the 24mm PCE, much the same as my old 35 PC on FX, but 4x larger and 16x the price... Most of the time, I'm using the 24 on a D700 with the limitations of the prism in the way when I rotate... That is overcome by using a modified TC-14e which works pretty well with both the 24mm PCE and 85 PC.
Since I still shoot both DX and FX, the advantage for me is having one lens that doubles as two focal lengths with no modifications a 24mm on the FX an a longer 35mm equivalent on the DX but both with auto aperture (yea!).
Another advantage with the 24 PCE on the DX is no vignetting like you get with extreme shifts on the FX, though I find I like that effect in my pix since it adds a retro extreme view camera movement.
Had I not found the 24 PCE on eBay, I would have rented the lens. Now that I have it and have used it quite a bit, I'm glad I have it, especially doing wider landscapes.