So I took a rented Schneider 50mm TS on a trip to the Eastern Sierra Nevada. Overall I'd say I'm not impressed. The build quality is very robust and the lens movements are secure, but that's about all it has going for it over the Nikon PC-E. While I didn't find the weight too objectionable, the size/bulk of this lens was surprising even though I knew it was going to be big. And when I rented it I hadn't considered that I wouldn't have a polarizer to use with it, so that cut down the lens' usefulness also.
Optically, the un-shifted/un-tilted image is good but not spectacular. As LLoyd noted you need to stop down a bit and even then there's some CA (it seemed worse in Lloyd's samples, but I'm not sure if that lens sample variation of just a matter of shooting conditions). Sharpness falls off a bit at the edge, and once you start shifting that becomes even more of an issue. Given that some CA is really the only optical weakness of the Nikon PC-E, I just don't see the Schneider lens as an upgrade from a purely optical standpoint (the Schneider definitely has better build quality though).
On the ergonomics side, I was also disappointed. The unidirectional shift is just a PITA, no way around it. I supposed I could get used to it if everything else about the lens was wonderful, but it's not. Oh, and don't get me started about the tripod collar - it's worthless IMHO. The problem is this: when using the tripod collar, you can't use either rotation axis of the lens to change the shift direction; you have to rotate the lens in the tripod collar, and the collar has no index markings so this quickly becomes far more trouble than it's worth. To add injury to insult, the tripod foot is too small to use with RRS lever-style QR clamps. So I quickly discarded the tripod collar after the first time trying to use it.
While I understand the theory of parallax-free stitching, the reality is that parallax is rarely an issue at 50mm; and even if you do have a close foreground you can avoid parallax by simply sliding the camera a bit left/right in the QR clamp to get the same effect. So to me this is not at all a selling feature of the lens, especially given the poor ergonomics required to actually use the tripod collar.