Is there really a difference in FoV? Wouldn't you just have more magnification in your viewfinder to produce the same FoV? With magnification you should be able to have whatever size view you want.
Quote: There should also be an aperture difference.
I understand why you might say that, but I don't agree. I want to see them both at the same aperture. Compensating for better DoF on an APS-C so that it doesn't have better DoF but has a wider aperture, I'm sure you can make both images look the same but why? Once you change the aperture, now you're in to changing shutter speeds or ISO , possibly changing the amount of light available to the sensor, creating issues of reciprocity and therefore noise. If I'm designing this test, I'd use do it the way jsherman did, approximately the same focal effective length and the same aperture.
What would be the point in changing the DoF so they were the same if the difference in aperture meant there would be shots you could take with the APS-C that you couldn't even take with the FF because of low light?