[mike]

 I'll need to try and see how DOF changes when doing 16mm on APS-C instead of 24mm FF. Should not be a great deal of difference of course, but any little bit helps. And I'm not one of those users who agonize over numbers and dismiss anything that isn't a 800mm f/0.95 level of shallow DOF.

I'm a little confused on what you're trying to do. If you put a 16mm lens your camera and put it in aps-c mode and compare it to a 24mm lens on the same camera in FF mode for the same aperture, you'll get ~1.5x greater dof and the same fov. Likewise, if you use an aperture of 2.8 on the FF, you will need to use 1.8 (~2.8/1.5) to have the same dof. But I assume you knew that already. 

I would expect the aps-c and the ff noise to be approximately the same at 100% on the screen - ignoring minor difference due to exposure times for say a typical shot. That, however, translates to more noise, ~1.5x, on an say anA3 print just by the virtue there are less pixels to cover the same area for the aps-c. The question is does it matter for your application?