17mm on FF MFDB is - as near as makes very little difference - the same as 11mm FoV on 35mm. I've been shooting with the 17TS-E on IQ180 for several years now (starting with the H-Cam, and then the Alpa FPS).In addition: setting the sony a7rii with the 17tse vertical and shifting with the hcam/mirex left and right to the edge of the image circle (which is app. 18mm left & right ) this results in a 85Mp image with a ratio of 2:3 and a field of view very similar than the 11mm lens and you can still shift up and down with the tse app. 5mm. Interesting setup too, at least in arch. and landscape photography with not moving subjects, the practical need for fov wider than 17mm is rare, but in this way even without having a wider lense in the bag this ultrawide range down to 11mm is easily (and shiftable) covered with the 17tse and the genial accessory of a second shift layer. The 17tse is really sharp all over the frame, as is the 24tse and the contax 35pc.
Interesting is also, that the 17tse seems to have a very similar image circle than the 11-24mm, i dont have the zoom but the front element of this both lenses looks very similar as well.
So yes, if you're going to shift the sensor of a 35mm camera around the lens' image circle, then the end result is indeed going to be very similar to 11mm on 35mm. Of course it is far more advantageous to us it on MF and capture everything in a single shot.
It should be noted that the 17TS-E is absolutely NOT "really sharp" all over the frame. It does start to fall apart in the corners at any aperture under around f/11 or so. The 24 TS-E is a lot sharper than the 17 across all apertures.
What's interesting is that with the introduction of the 11-24, there are now "11mm FoV 35mm equivalent" options for all formats -
17 TS-E on the IQ180
11-24 at 14mm on an IQ250
11-24 at 11mm on 35mm.
The front elements of the 11-24 and the 17TS-E, whilst superficially similar, are very different sizes.
Kind regards,
Gerald.
/edit
(Should probably mention that it's the diagonal FoV that I'm referring to. Obviously you have to consider the different aspect ratios as well - 35mm will give you wider horizontal but shorter vertical FoV.)