I received my housing on Friday - very nice! It still seems nice and compact - I don't have my Em1 housing to compare it to but from the top of the cold shoe to the bottom of the housing is about 7 inches. A couple of improvements - there is a spot on the top left back corner that you can use for the vacuum- it angles slightly down so it will be a bit easier to vacuum once the focus light and strobes are attached. The front shutter lever is different than Em1 housing - should make it easier to use- especially if using the back lever to focus.
The camera does fit into the housing with the standard flash that comes with the camera.
There are a number of other improvements but as always Nauticam has done a great job with this housing. The price of the housing is only $50 more than previous model - which makes the housing less than the camera.
I have pre-ordered the housing- I was told the first housings should be shipping before the end of the month. if you want this housing- I would suggest pre-ordering it - it will depend where you are on the pre-order list and how popular the housing is.