I'd like to know in more detail too, it is a bit hard to find out since the Rodenstocks/Schneiders are rarely tested, one have to find shots here and there on the net and guess from that. The 24mm TS-E II has much better performance than the PC-E 24mm for sure, I have one myself. It is also not as handicapped in movements like the PC-E 24 either. What I do know is that the DSLR lenses get corner sharpness issues at high resolution (the TS-E 24 too), but I don't know for sure how large corner sharpness issues on the wides are for the Rodenstock/Schneiders, maybe problems are larger than I think there.
For me personally the comparison Nikon D800 + PC-E 24 vs Aptus 75 + Schneider 35 XL would be a great test. About the same amount of pixels, same FOV, both able to tilt and shift. I plan to get a 35 XL but don't have it yet unfortunately.
Comparing the 23mm Rodenstock with 70mm image circle with the TS-E 24 II is an interesting lens quality test (would not be surprised if the TS-E wins, it is a great lens), but system-wise it is more relevant to compare it with a 35mm or a 40mm with 90mm image circle. 135 digital only has 36x24mm sensors so they need shorter focal lengths and higher lpmm numbers than a 48x36 or 54x41mm sensor to achieve the same FOV and resolution.
I don't think it is that valuable to mix in price into the equation, speciality products like MF is very expensive and will always have poor price/performance compared to mass-market products. If MF has something to offer and is not too expensive for the professional then it is ok, but if it is just expensive without offering anything then it is worthless...
Thanks for taking the time to reply.
Regarding your third paragaph, I think we're both coming at this from slightly different perspectives.
My 23 vs 24 comparison is because a 23 Rodenstock on an Alpa with a IQ180 back will give (almost) the same FoV as a 24 TS-E on the HCam with the same IQ180 back. For me, this is one of the decisions I need to make in the coming months. I want to go wide angle with my IQ180, and need to decide which option to go with - I can't see myself affording (or indeed, wanting) both.
I recognise that if you're doing a MF vs 135 comparison, then it's not valid due to the different sensor sizes.
Regarding your final paragaph, I'm not so convinced that the professional and amateur approach to this subject is particularly different - both will certainly take price into consideration.
For the "true" professional (i.e. one whose primary source of income is derived from photography), there are of course fairly simple ROI calculations to determine whether or not it is worth investing in particular pieces of kit. At the end of the day, those calculations are very much impacted by the capital outlay necessary and depreciation over time, so price is important.
For an amateur (such as myself), MF of course has a barrier to entry based on price, but once you've decided that you're prepared to spend what it takes to join the game, there will always be choices to be made, and those choices will be driven primarily on bang for the buck. For me right now, it's Alpa + one lens, or HCam + several lenses, for the same investment. And if one of those lenses meets or beats the one lens on the Alpa, then (of course based on personal requirements) it's a no-brainer.
The existence of cameras such as the HCam really do break down the technical barriers between MF and 135, and give one the option of cherry-picking the best bits of kit from both worlds. Given that (apparently) there are a range of 135 lenses that are just as good as - if not better than - the best of the MF digital lenses, it wouldn't surprise me if there were further developments in this area.