There sems to be a noticable difference between a still snapshot and the original, which I haven't seen in MEP 2014. Here's an example of a 1 sec clip followed by a snapshot of its last frame. I've included 4 cycles so that the differnce can be seen as 'flashing'.
https://dl.dropboxusercontent.com/u/4019461/Differences.mp4
EDIT: That's odd. I don't see the difference I described in the above MP4, made in MEP. Yet it's very clear in the MEP preview. So I've made another MP4 after capturing that (with CamStudio):
https://dl.dropboxusercontent.com/u/4019461/DifferencesInPreview.mp4