The old diorama's where definatly beautifull, but I can see why they changed it, so that its more informative about the content.
Some sets do seem to have far more or far less in them than you might expect.
A good compromise would be to put a nice diorama on the back of the manual, to get the best of both worlds. Good info before you buy the set, and something nice to look at once you aquired it. Aside from the playmobil in the box of course.