Jerry,
From an optics, build quality, and customer service standpoint, Z-R are fantastic. From a Quality Control standpoint, I still have my complaints - my 7x43 ED3 appears to be a very poor sample as the rubber armoring appears to be detaching from the underlying body and the outer sheath of the focus-knob separated. To the credit of Z-R, they quickly responded to my email and will likely replace the binocular with a better sample. I have looked through the 7x42 SLC Neu and 7x42 Trinovid BN and though I prefer other things, ergonomically, with those models, I believe the ED3 is distinctly superior from an optics standpoint.
I have not handled the Z-R Prime, but owned the Leupold BX-4 McKinley which is a very similar binocular. For me, it ranks right below some of the alphas I've handled (my favorite being the 8x42 SLC HD). Sharp, little CA, quite flat throughout the FoV but not a strong "rolling ball" effect, great ergonomics (personal), very good mechanics/build quality. I believe its issue is primarily that the large eyecups made the binocular unusable by some; Leupold is releasing a BX-4 with redesigned eyecups and I wonder if Z-R will follow suit.
Justin