I have a hard time to see why tech cam flat stitching would be better than 35mm camera (say a D800) on a high quality pano head with lens at nodal point (it is not *that* hard to tune). Tech cam stitching with geared movements is much slower compared to a click-stopped pano head. There's the stitching backs from Kapture group et al of course, but not many use them. Heavy to carry around.
With the pano head you always use the best center portion of the lens. Projection is chosen in post-processing, and for wide-angle landscape panos cylindrical is often better then rectilinear, but you can do rectilinear as well of course. There'll be some pixel stretching but you use over-resolution to handle that.
If one's doing composite images with stitching (and to some extent focus stacking) I think the gap between 35mm digital and MF tech cam is considerably smaller.
The main advantage for me using my Linhof Techno is the one-shot image. To me a one-shot image is higher valued than a composite, I just think it is more "true" photography. I have done stitching and large prints from it so I'm not against it, but I'm most proud of my one-shot images. And for one-shot images there is a large value of shift with high quality large image circles and tilt/swing and I think MF tech cams have a quite good lead there.
For me as an amateur price/performance has importance too. I bought almost all my MF gear second hand, so my 33 megapixel tech cam system costs "only" about twice the corresponding D800 system would have cost new. Yes price/performance is worse even when comparing second hand MF with new 35mm but it is a long-term investment, low enough purchase price for me to handle and the lens/flexibility performance aspect is better.
I think tech cams and lenses are reasonably priced. But the often silly high prices of new MFDBs is a real turnoff, here in Sweden a new 33 megapixel back costs €25,000 with VAT ($32,000), which is about 10 times a 36 megapixel D800. If it is not possible to make entry-level MFDBs substantially cheaper I think the whole MF business is threatened in the long-term. 2 - 3 higher price for similar performance I think is ok, but not 10 times... I should say though that Leaf pricing in Sweden seems totally broken. Would I buy a new MFDB today it would be a Hasselblad CFV-50, it costs €14,000 with VAT here, that is despite 50 megapixels much cheaper than the Leaf Aptus-II 7 and also Phase One P45+.