If I can get away with it, I'd rather use a good quality wider angle lens such as the Nikkor 14-28/2.8, and use the perspective type controls in PS. In addition to 'perspective', there's 'distort' and 'warp'. Using a combination of these tools, one should be able to mimic any effect one would get with a shift lens.
The issue of better quality that could result from using a dedicated shift lens is of concern, of course. However, I haven't done any comparisons. Has anyone done any comparisons? One shouldn't just assume that the PC lens will produce better results.
On the face of it, one might assume if one pulls out the corners, loses part of the image, extrapolates pixels that are further away from the corners and sides, one simply ends up diluting resolution.
On the other hand, the resolution of shift lens at the edges of maximum shift tends to be rather poor anyway. A good lens like the Nikkor 14-28 is reported to be sharp right to the edges. Slightly away from the edges and corners, it should be even sharper. Extrapolate those (sharper) pixels that are slightly away from the edges and corners and it's quite possible that the resolution in the corners will be no worse than the result from the PC lens. Who knows! In some cases perhaps better, depending on the lens.
(Mark Welsh, please sort out those delays with your Nikon/Canon adapter )
ps. I should add that my standard for 24mm PC lenses is the Canon TS-E 24. I would hope that images from the Nikkor 14-28, after perspective type adjustments in PS, would be at least as good. It will be interesting to do a comparison... when I get my adapter.