Upload & Sell: Off
It is odd that the screen might be off, since when I first started using the 100 MP, I was nailing almost all my shots, but now it seems that there is a problem. Perhaps I should try to re-seat the screen, in case it just got a jolt, or got a bit loose?
In hindsight I see what you mean with my relationship with the 50 MP, so I should probably state things a little less ambiguously: the 50 MP is a really great lens, and I cannot imagine selling it again. It has astounding performance, with virtually no CA anywhere under any conditions, and it is sharp as can be, even wide open. The shape and size are pretty close to perfect, and now that I have used it a bit, the focusing ring has a very nice firm smoothness to it.
It has just two minor issues, which cause me to wonder if I should add (not replace with) a 50 Planar: the DoF is rather large at all apertures, and to get real background blur requires moving in quite close. Secondly, the far corners appear to have some field curvature, which doesn't bother with my style of photography, but is something to keep in mind. The large DoF could be an advantage for example for landscape photography, as you mentioned.