This question sufficiently basic and qualitative that it belongs in General Physics instead of the more specialized sub forums.
Goodver, the question will remain open until you answer it for yourself. We are not going to spoon feed you an answer. You've been given one very good hint that should start you in the right direction. Have you followed up on that one yet?
Hello Nugatory, I understand that soft x-ray requires usage of synchrotron, and therefore should be more expensive etc. But my question related to quantitative properties of image rather then financial issues. Therefore, from my understanding, the quality of both images should not differ significantly as in both cases the crucial point is a usage of wave properties. Unless I am missing some additional physics which influence imaging, and about which I am asking in this topic.