...why Draw zooms in a bit faster into an object with e.g. a shadow:

CorelDraw seems to create an initial bitmap (with a very high resolution). When you zoom in, the bitmap stays the same. Draw needs very long to create that shadow-bitmap. When you change the shadow transparency in Draw, it creates a new bitmap (and once again this takes quite a long time).

On the other hand, Xara seems to render a new shadow-bitmap (it's resolution depending on the zoom factor) whenever you zoom into the object.
Xara obviously renders shadow-bitmaps much faster than Draw: changing shadow transparency can be done (almost) in realtime (depending on how fast your PC is).

Am I right?