Ok, we agree.
For me stitching isn't just about aspect ratio, it is about added resolution also.
And 95% of the thousands of stitches I have made in the past 10+ years were with a dedicated pano head.
Cheers,
Bernard
I look at it in terms of effective sensor area and pixels per inch at final print size.
Shift-stitching using a lens that can go 12mm in each direction gives me an effective sensor area of 24x60mm horizontally, or 36x48mm vertically. This gives an effective sensor width equal to or greater than Phase One digital backs (since most of my shots are between 1:2 and 1:3 aspect ratio, the height limitation doesn't come into play much). A 1.4x TC increases this to 24x70mm horizontally or 36x58mm vertically, although obviously at a different focal length. A single frame from a modern MFDB contains a lot of detail - as much as a large-format film shot - and is suitable for printing at a large size.
PPI is another issue. Shift-stitched horizontally (without TC), an A7r2 gives me enough pixels for 150ppi at almost 90" print width. A 60MP 24x36mm sensor would give me enough for around 105", or 200ppi at greater than 72" width (for a 24x72" print), while 70MP would give enough for 115".
For a shift-stitched panorama, the effective sensor area and PPI are evenly distributed - there is as much in the corner as thete is in the centre.
Effective sensor area and PPI for rotational panoramas are a bit more difficult to calculate, depending on the angle of view of the final image, the projection (rectilinear, cylindrical or spherical) as well as the focal length of the lens. Not only that, but it's unevenly distributed - there is more sensor area and more PPI contributing to the centre of the image than the corners. You can calculate what focal length you need to shoot at (and how many frames it will take) to get the same or more PPI and sensor area contributing to the corners on a rotational panorama as compared to a shifted panorama. The sharpness aspect is somewhat mitigated by the fact that the rotational panorama uses the sharper part of the lens than the shifted edge of a tilt-shift, but the effective sensor area and its implications in terms of noise still apply. If you don't have enough sensor area contributing to the corners, if they're stretched from too small an area of sensor, you'll have noisy corners, regardless of how sharp the lens you shot it with is.