I use the 45mm 67 lens on my mamiya zd with the zörk adapter (also the 55mm, 75mm, 105mm for the 67). they are all very good lenses. the 45mm is pretty sharp but has some CA. If you use the 45mm without shift, the CA is symmetrical and can be easily corrected. when you use it with the zörk and you shift a lot, the CA is more difficult to correct since it is the unsymmetric. Since I use it alway with shift I use the lightroomfunction of "remove all CA around borders" (all something like that) which handles the CA quite well. But there is also quite a bit wavelike distortion when fully shifted that is not so easy to correct.
stefan