I haven't compared the two but regardless of which one you decide going with, you should check out the Stage Manager which is one of the tools in the DMTS and which allows you to create, orient and position placeables and then store the spatial information about those placeables and "unpack" them into scenes later. You can also use the same placeable orientation tools to move around placeables in-game to give, for instance,
the effect of one ship pulling alongside another at sea.
If you have CEP 2.3 installed, the PDF for the stage manager is in your docs\\cep folder in your NWN install. (dmts.pdf)
If you haven't used it before and there's nobody there to give a demo it'll probably take all of about 10 minutes to figure out. The pdf is pretty thorough but once you actually start playing with it you start getting new ideas about how it can be used. I know there's some threads on the
CEP home forums which go into more detail about some of the other aspects of the system.