As far as apps are concerned, screen display, dev talk, the team over at the BlackBerry Dev Blog have broken down the comparison to the Z30, Z10 and Q10.
First off, know the differences (when developing):
As you can see, the BlackBerry Z30 display is larger and has a more narrow aspect ratio than the BlackBerry Z10, therefore, we need to be careful while designing our apps so that there are no cropped images, or overlapping components.
The camera features are the same across all three devices, so there is no need for adjustments there.
The BlackBerry Z30 comes with a more powerful processor than the BlackBerry Z10 or BlackBerry Q10, giving us higher graphics capabilities.
All other features are common across all three devices, the exception being that the BlackBerry Q10 has a physical keyboard and the others have a full touch screen.
Great breakdown! For more info as far as porting, cascades, WebWorks and more head on over to the BlackBerry Dev Blog.