I’m not an expert, but maybe
…starting with the input transformer, and real physical impedance
switching when used with Apollo’s Unison technology
Might be the reason for the DSP units. It’s, as far as I can tell, not only to take the load of your workstation but there are other technology application being performed within the DSP. I might be wrong, I am not claiming to be right. But it makes sense.
I just A/B’d a few demo’s, the SPL etc… the difference really is when they are pushed, they really shine. There is noticable difference in quality of sound, preference maybe? But I find the majority of UAD-2 plugins I have bought to be very high quality. I still am not convinced about the pricing.
Maybe I am wrong though, but if I am right then that means you’d need to do some serious work to have the behaviour described to be the same for a native VST plugin installed normally.
??? suggestions or am I wrong?