I see that you posted the bug report about the undesired behavior when viewing the crop window/guides.
(I checked my old install of LR4.4 and it does not do the same thing)
And I remember at least for the first version of LR5 it worked without the jumpy display of the cropped image.
If you dig around in the other bug reports it looks like it came up when version 5.2? was released.
I cannot remember when I first noticed it myself, it is most noticeable when changing between that are different aspect ratios/crop locations.
Moving between photos that are all cropped to same aspect/location and it is much better. It is like it remembers the crop view of the previous photo then updates to show current one.
